JP2011246820A - Iron-based nanosize particle and method for producing the same - Google Patents
Iron-based nanosize particle and method for producing the same Download PDFInfo
- Publication number
- JP2011246820A JP2011246820A JP2011153409A JP2011153409A JP2011246820A JP 2011246820 A JP2011246820 A JP 2011246820A JP 2011153409 A JP2011153409 A JP 2011153409A JP 2011153409 A JP2011153409 A JP 2011153409A JP 2011246820 A JP2011246820 A JP 2011246820A
- Authority
- JP
- Japan
- Prior art keywords
- particles
- powder
- coating layer
- iron
- metal
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Granted
Links
- XEEYBQQBJWHFJM-UHFFFAOYSA-N Iron Chemical compound [Fe] XEEYBQQBJWHFJM-UHFFFAOYSA-N 0.000 title claims abstract description 146
- 239000002245 particle Substances 0.000 title claims abstract description 139
- 229910052742 iron Inorganic materials 0.000 title claims abstract description 66
- 238000004519 manufacturing process Methods 0.000 title claims description 16
- 239000011247 coating layer Substances 0.000 claims abstract description 42
- 239000002923 metal particle Substances 0.000 claims abstract description 42
- 229910052751 metal Inorganic materials 0.000 claims abstract description 29
- 239000002184 metal Substances 0.000 claims abstract description 26
- 239000000203 mixture Substances 0.000 claims abstract description 23
- 229910052796 boron Inorganic materials 0.000 claims abstract description 13
- 229910052782 aluminium Inorganic materials 0.000 claims abstract description 11
- 229910052785 arsenic Inorganic materials 0.000 claims abstract description 11
- 229910052758 niobium Inorganic materials 0.000 claims abstract description 10
- 150000004767 nitrides Chemical class 0.000 claims abstract description 10
- 229910052726 zirconium Inorganic materials 0.000 claims abstract description 10
- 229910052719 titanium Inorganic materials 0.000 claims abstract description 9
- 229910052720 vanadium Inorganic materials 0.000 claims abstract description 9
- 229910052804 chromium Inorganic materials 0.000 claims abstract description 8
- 229910052738 indium Inorganic materials 0.000 claims abstract description 8
- 229910052748 manganese Inorganic materials 0.000 claims abstract description 8
- 229910052715 tantalum Inorganic materials 0.000 claims abstract description 8
- 229910052727 yttrium Inorganic materials 0.000 claims abstract description 8
- 239000000843 powder Substances 0.000 claims description 80
- 229910052759 nickel Inorganic materials 0.000 claims description 44
- 239000002105 nanoparticle Substances 0.000 claims description 35
- 239000011812 mixed powder Substances 0.000 claims description 15
- 238000002156 mixing Methods 0.000 claims description 14
- 229910052684 Cerium Inorganic materials 0.000 claims description 7
- 230000001590 oxidative effect Effects 0.000 claims description 7
- 230000005291 magnetic effect Effects 0.000 abstract description 53
- 230000003647 oxidation Effects 0.000 abstract description 14
- 238000007254 oxidation reaction Methods 0.000 abstract description 14
- 229910052799 carbon Inorganic materials 0.000 abstract description 5
- 150000002505 iron Chemical class 0.000 abstract 1
- 230000005415 magnetization Effects 0.000 description 21
- 239000012071 phase Substances 0.000 description 21
- 238000002441 X-ray diffraction Methods 0.000 description 14
- 238000010438 heat treatment Methods 0.000 description 14
- 229910002546 FeCo Inorganic materials 0.000 description 13
- PNEYBMLMFCGWSK-UHFFFAOYSA-N aluminium oxide Inorganic materials [O-2].[O-2].[O-2].[Al+3].[Al+3] PNEYBMLMFCGWSK-UHFFFAOYSA-N 0.000 description 13
- 230000007797 corrosion Effects 0.000 description 13
- 238000005260 corrosion Methods 0.000 description 13
- 238000000034 method Methods 0.000 description 11
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 description 10
- 230000000052 comparative effect Effects 0.000 description 10
- 239000001301 oxygen Substances 0.000 description 10
- 229910052760 oxygen Inorganic materials 0.000 description 10
- KFZMGEQAYNKOFK-UHFFFAOYSA-N Isopropanol Chemical compound CC(C)O KFZMGEQAYNKOFK-UHFFFAOYSA-N 0.000 description 9
- 239000010419 fine particle Substances 0.000 description 9
- 229910000859 α-Fe Inorganic materials 0.000 description 9
- 229910020599 Co 3 O 4 Inorganic materials 0.000 description 8
- 229910045601 alloy Inorganic materials 0.000 description 8
- 239000000956 alloy Substances 0.000 description 8
- PZNSFCLAULLKQX-UHFFFAOYSA-N Boron nitride Chemical compound N#B PZNSFCLAULLKQX-UHFFFAOYSA-N 0.000 description 7
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 description 7
- 238000001816 cooling Methods 0.000 description 7
- IJGRMHOSHXDMSA-UHFFFAOYSA-N Atomic nitrogen Chemical compound N#N IJGRMHOSHXDMSA-UHFFFAOYSA-N 0.000 description 6
- 230000015572 biosynthetic process Effects 0.000 description 6
- 239000011248 coating agent Substances 0.000 description 6
- 238000000576 coating method Methods 0.000 description 6
- 229910001873 dinitrogen Inorganic materials 0.000 description 6
- 229910052582 BN Inorganic materials 0.000 description 5
- 230000007423 decrease Effects 0.000 description 5
- 239000002994 raw material Substances 0.000 description 5
- 238000003917 TEM image Methods 0.000 description 4
- 238000005275 alloying Methods 0.000 description 4
- 239000011324 bead Substances 0.000 description 4
- 238000006243 chemical reaction Methods 0.000 description 4
- 150000001875 compounds Chemical class 0.000 description 4
- 239000012535 impurity Substances 0.000 description 4
- 238000007885 magnetic separation Methods 0.000 description 4
- 239000000463 material Substances 0.000 description 4
- 238000000691 measurement method Methods 0.000 description 4
- 238000001556 precipitation Methods 0.000 description 4
- 229910017061 Fe Co Inorganic materials 0.000 description 3
- 229910002555 FeNi Inorganic materials 0.000 description 3
- 229910001566 austenite Inorganic materials 0.000 description 3
- 239000006229 carbon black Substances 0.000 description 3
- 238000010586 diagram Methods 0.000 description 3
- 230000000694 effects Effects 0.000 description 3
- 238000000635 electron micrograph Methods 0.000 description 3
- 229910002804 graphite Inorganic materials 0.000 description 3
- 239000010439 graphite Substances 0.000 description 3
- 239000006249 magnetic particle Substances 0.000 description 3
- 239000012528 membrane Substances 0.000 description 3
- 230000035699 permeability Effects 0.000 description 3
- 238000006722 reduction reaction Methods 0.000 description 3
- 229910018072 Al 2 O 3 Inorganic materials 0.000 description 2
- 229910020630 Co Ni Inorganic materials 0.000 description 2
- 229910002440 Co–Ni Inorganic materials 0.000 description 2
- UQSXHKLRYXJYBZ-UHFFFAOYSA-N Iron oxide Chemical compound [Fe]=O UQSXHKLRYXJYBZ-UHFFFAOYSA-N 0.000 description 2
- 239000006096 absorbing agent Substances 0.000 description 2
- 230000002776 aggregation Effects 0.000 description 2
- 238000004458 analytical method Methods 0.000 description 2
- 239000012620 biological material Substances 0.000 description 2
- 230000005540 biological transmission Effects 0.000 description 2
- 238000000354 decomposition reaction Methods 0.000 description 2
- 230000006866 deterioration Effects 0.000 description 2
- 238000007580 dry-mixing Methods 0.000 description 2
- 239000007789 gas Substances 0.000 description 2
- 229910052598 goethite Inorganic materials 0.000 description 2
- 229910052739 hydrogen Inorganic materials 0.000 description 2
- AEIXRCIKZIZYPM-UHFFFAOYSA-M hydroxy(oxo)iron Chemical compound [O][Fe]O AEIXRCIKZIZYPM-UHFFFAOYSA-M 0.000 description 2
- 230000006872 improvement Effects 0.000 description 2
- 150000002500 ions Chemical class 0.000 description 2
- 239000010977 jade Substances 0.000 description 2
- 239000010410 layer Substances 0.000 description 2
- 238000005259 measurement Methods 0.000 description 2
- 239000004570 mortar (masonry) Substances 0.000 description 2
- PXHVJJICTQNCMI-UHFFFAOYSA-N nickel Substances [Ni] PXHVJJICTQNCMI-UHFFFAOYSA-N 0.000 description 2
- 239000002904 solvent Substances 0.000 description 2
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 2
- VHUUQVKOLVNVRT-UHFFFAOYSA-N Ammonium hydroxide Chemical compound [NH4+].[OH-] VHUUQVKOLVNVRT-UHFFFAOYSA-N 0.000 description 1
- ZOXJGFHDIHLPTG-UHFFFAOYSA-N Boron Chemical compound [B] ZOXJGFHDIHLPTG-UHFFFAOYSA-N 0.000 description 1
- 229910003321 CoFe Inorganic materials 0.000 description 1
- 229910005191 Ga 2 O 3 Inorganic materials 0.000 description 1
- UFHFLCQGNIYNRP-UHFFFAOYSA-N Hydrogen Chemical compound [H][H] UFHFLCQGNIYNRP-UHFFFAOYSA-N 0.000 description 1
- 229910001374 Invar Inorganic materials 0.000 description 1
- 229910001030 Iron–nickel alloy Inorganic materials 0.000 description 1
- 229910010413 TiO 2 Inorganic materials 0.000 description 1
- 238000005054 agglomeration Methods 0.000 description 1
- 238000004220 aggregation Methods 0.000 description 1
- 235000011114 ammonium hydroxide Nutrition 0.000 description 1
- 230000008901 benefit Effects 0.000 description 1
- 239000003575 carbonaceous material Substances 0.000 description 1
- 239000005539 carbonized material Substances 0.000 description 1
- 238000000975 co-precipitation Methods 0.000 description 1
- 239000011362 coarse particle Substances 0.000 description 1
- 239000000470 constituent Substances 0.000 description 1
- 239000007771 core particle Substances 0.000 description 1
- WEHWNAOGRSTTBQ-UHFFFAOYSA-N dipropylamine Chemical compound CCCNCCC WEHWNAOGRSTTBQ-UHFFFAOYSA-N 0.000 description 1
- 239000006185 dispersion Substances 0.000 description 1
- 238000001035 drying Methods 0.000 description 1
- 238000010828 elution Methods 0.000 description 1
- 230000001747 exhibiting effect Effects 0.000 description 1
- 230000005307 ferromagnetism Effects 0.000 description 1
- 239000001257 hydrogen Substances 0.000 description 1
- 238000001027 hydrothermal synthesis Methods 0.000 description 1
- 239000011261 inert gas Substances 0.000 description 1
- 229940087654 iron carbonyl Drugs 0.000 description 1
- SZVJSHCCFOBDDC-UHFFFAOYSA-N iron(II,III) oxide Inorganic materials O=[Fe]O[Fe]O[Fe]=O SZVJSHCCFOBDDC-UHFFFAOYSA-N 0.000 description 1
- JEIPFZHSYJVQDO-UHFFFAOYSA-N iron(III) oxide Inorganic materials O=[Fe]O[Fe]=O JEIPFZHSYJVQDO-UHFFFAOYSA-N 0.000 description 1
- 238000005304 joining Methods 0.000 description 1
- 239000007791 liquid phase Substances 0.000 description 1
- 239000000696 magnetic material Substances 0.000 description 1
- 229910044991 metal oxide Inorganic materials 0.000 description 1
- 150000004706 metal oxides Chemical class 0.000 description 1
- 239000011859 microparticle Substances 0.000 description 1
- 230000007935 neutral effect Effects 0.000 description 1
- 229910052757 nitrogen Inorganic materials 0.000 description 1
- 239000005416 organic matter Substances 0.000 description 1
- 239000003960 organic solvent Substances 0.000 description 1
- 230000005298 paramagnetic effect Effects 0.000 description 1
- 230000005408 paramagnetism Effects 0.000 description 1
- 229910052761 rare earth metal Inorganic materials 0.000 description 1
- 230000009257 reactivity Effects 0.000 description 1
- 230000009467 reduction Effects 0.000 description 1
- 229920006395 saturated elastomer Polymers 0.000 description 1
- 239000000126 substance Substances 0.000 description 1
- 239000006228 supernatant Substances 0.000 description 1
- 238000001308 synthesis method Methods 0.000 description 1
- 230000002194 synthesizing effect Effects 0.000 description 1
- 238000005979 thermal decomposition reaction Methods 0.000 description 1
- 230000009466 transformation Effects 0.000 description 1
- 230000007704 transition Effects 0.000 description 1
- 238000001947 vapour-phase growth Methods 0.000 description 1
Abstract
Description
本発明は、磁気テープ、磁気記録ディスクなどの磁気記録媒体や、電波吸収体、インダクタ、プリント基板等の電子デバイスや、生体物質抽出用の磁気ビーズなどに使用される鉄系ナノサイズ粒子およびその製造方法に関する。 The present invention relates to a magnetic recording medium such as a magnetic tape or a magnetic recording disk, an electronic device such as a radio wave absorber, an inductor or a printed board, an iron-based nano-sized particle used for a magnetic bead for extracting a biological material, It relates to a manufacturing method.
電子機器の小型軽量化に伴い、電子デバイスを構成する材料自体も従来のミクロンサイズからナノサイズへと小粒子化が要求されている。しかも、同時に電子デバイスの高性能化も必要とされている。例えば特許文献１には、磁気記録密度を向上させるために、磁気テープに塗布する磁性粒子には、磁化が高くかつナノサイズの粒子であることが要求されることが記載されている。このナノサイズ粒子としては、フェライトやマグネタイトなどの酸化物粒子または金属粒子を使用することが可能であるが、性能面では磁化が大きい金属粒子が好ましい。金属からなるナノサイズ粒子は、通常共沈法や水熱合成法などで代表される液相合成法により製造されている。また最近では、このナノサイズ粒子を金属有機物の熱分解を利用して製造することも行われている。例えば、特許文献２には、Ｆｅ（ＣＯ）５からＦｅを主体とするナノサイズ粒子を合成する方法が記載されている。また、特許文献３にはプラズマの熱を利用した気相成長法で被覆金属微粒子を生成することが記載されている。 Along with the reduction in size and weight of electronic devices, the material itself of electronic devices is required to be reduced in size from the conventional micron size to nano size. At the same time, there is a need for higher performance electronic devices. For example, Patent Document 1 describes that magnetic particles applied to a magnetic tape are required to be high-magnetization and nano-sized particles in order to improve magnetic recording density. As the nano-sized particles, oxide particles such as ferrite and magnetite or metal particles can be used, but metal particles having large magnetization are preferable in terms of performance. Nano-sized particles made of metal are usually produced by a liquid phase synthesis method typified by a coprecipitation method or a hydrothermal synthesis method. Recently, the nano-sized particles are also produced by utilizing the thermal decomposition of metal organic matter. For example, Patent Document 2 describes a method of synthesizing nanosized particles mainly composed of Fe from Fe (CO) 5. Patent Document 3 describes that coated metal fine particles are generated by a vapor phase growth method using the heat of plasma.
上記ナノサイズ粒子に含まれるＦｅは、一般的に常温・常圧下で体心立方晶構造のα相が安定であるが、非特許文献１に記載されているように、粒子サイズが７５ｎｍよりも微細化すると面心立方晶構造のγ相が常温・常圧下で安定に存在することが知られている。しかし上記γ相は室温で常磁性を示すため、γ相の出現はＦｅ系ナノサイズ粒子の磁気特性低下の原因となる。なお微小γ−Ｆｅ粒子は単純冷却によってはα相へと変態せず、その変態は応力などの外力によって誘起される。 Fe contained in the nano-sized particles is generally stable in the α phase of the body-centered cubic structure at normal temperature and pressure, but as described in Non-Patent Document 1, the particle size is more than 75 nm. It is known that the gamma phase having a face-centered cubic structure exists stably at normal temperature and pressure when refined. However, since the γ phase exhibits paramagnetism at room temperature, the appearance of the γ phase causes a decrease in the magnetic properties of the Fe-based nanosized particles. The fine γ-Fe particles are not transformed into the α phase by simple cooling, and the transformation is induced by an external force such as stress.
さらに、金属粒子は酸化し易いため、大気中で取り扱うと、磁気特性が劣化してしまう、あるいは粒子が激しく酸化して燃えてしまうといった問題が生ずる。そこで、例えば粒径が１μｍ以下の金属粒子を製造する場合、金属粒子表面の酸化を防止するため、金属粒子表面に耐酸化被膜を形成することが不可欠である。例えば特許文献４には、金属粒子に炭素質物質および金属含有物質を用いた高温熱処理等を施してグラファイトを被覆することが記載されている。 Furthermore, since metal particles are easily oxidized, handling them in the air causes problems such as deterioration of magnetic properties or intense oxidation and burning of particles. Therefore, for example, when producing metal particles having a particle size of 1 μm or less, it is indispensable to form an oxidation-resistant film on the metal particle surface in order to prevent oxidation of the metal particle surface. For example, Patent Document 4 describes that graphite is coated by subjecting metal particles to high-temperature heat treatment using a carbonaceous material and a metal-containing material.
特許文献４に記載された方法で、Ｆｅを主成分とする鉄系ナノサイズ粒子を被覆すると、生産効率が低下するという問題がある。また、従来の組成では、Ｆｅからなる金属粒子が微細化すると面心立方晶構造を有する常磁性のγ相が析出するため、磁気特性が低下するという問題がある。また、ナノサイズ金属粒子における耐食性被膜の膜厚は金属部分の直径より小さいことが望ましいが、十分な耐食性を得るためには金属部分の直径より大きくなってしまう場合が多かった。これでは折角ナノサイズ粒子を作製しても、被覆層の厚みが厚いとナノサイズ粒子としての意味を為さなくなってしまう。 When iron-based nano-sized particles containing Fe as a main component are coated by the method described in Patent Document 4, there is a problem that production efficiency decreases. Further, in the conventional composition, when the metal particles made of Fe are made finer, a paramagnetic γ phase having a face-centered cubic structure is precipitated, so that there is a problem that magnetic characteristics are deteriorated. Further, the film thickness of the corrosion-resistant coating on the nano-sized metal particles is preferably smaller than the diameter of the metal part, but in many cases, it becomes larger than the diameter of the metal part in order to obtain sufficient corrosion resistance. Even if nano-sized particles are produced, the meaning of the nano-sized particles is lost if the coating layer is thick.
したがって、本発明の目的は薄くても耐酸化性に優れた被覆を有し且つ磁気特性に優れた鉄系ナノサイズ粒子を提供することである。
本発明の他の目的は、高い磁化を有し、かつ耐酸化性に優れた鉄系ナノサイズ粒子を効率よく得ることのできる製造方法を提供することである。
Accordingly, an object of the present invention is to provide iron-based nano-sized particles having a coating with excellent oxidation resistance even when thin and having excellent magnetic properties.
Another object of the present invention is to provide a production method capable of efficiently obtaining iron-based nano-sized particles having high magnetization and excellent oxidation resistance.
上記目的を達成するために、本発明者らは、鋭意検討した結果、Ｆｅを主成分とし、ＣｏおよびＮｉのうち少なくとも一種を含む鉄系ナノサイズ粒子が、耐酸化性、磁気特性に優れること、特にＦｅ系組成にＣｏまたはＣｏとＮｉを添加して、Ｆｅ−Ｃｏ系の２元系組成またはＦｅ−Ｃｏ−Ｎｉ系の３元系組成とすることにより、γ相の析出が抑制されることを見出した。また、炭素被覆層または炭素を主成分とする被覆層、または特定の金属酸化物もしくは金属窒化物の被覆層を形成することにより、金属粒子の酸化が防止されることを見出し、本発明に至った。 In order to achieve the above object, as a result of intensive studies, the present inventors have found that iron-based nanosized particles containing Fe as a main component and containing at least one of Co and Ni have excellent oxidation resistance and magnetic properties. In particular, by adding Co or Co and Ni to the Fe-based composition to obtain a Fe-Co-based binary composition or an Fe-Co-Ni-based ternary composition, precipitation of the γ phase is suppressed. I found out. Further, it has been found that the formation of a carbon coating layer, a coating layer containing carbon as a main component, or a coating layer of a specific metal oxide or metal nitride prevents oxidation of metal particles, leading to the present invention. It was.
本発明の鉄系ナノサイズ粒子は、Ｆｅを主成分とし、ＣｏおよびＮｉのうちの少なくとも一種を含む組成を有する球状の金属粒子であり、膜厚が１〜２００ｎｍの被覆層を有することを特徴とする。Ｆｅを主成分とし、ＣｏおよびＮｉのうちの少なくとも一種を含むことにより、磁気特性を向上させることができると同時に、コアとなる金属粒子の耐蝕性も向上させることができる。十分な耐蝕性を保つには前記膜厚の下限を１ｎｍ以上とする。さらに鉄系ナノサイズ粒子として十分な磁気特性を発現するために前記膜厚の上限を２００ｎｍとする。高磁気特性の観点からは、より好ましくは４０ｎｍ以下である。前記金属粒子の粒径はナノサイズ、すなわち１〜１０００ｎｍの範囲にあることが望ましいが、１０〜１０００ｎｍの範囲にあることがより望ましい。球状とは、紡錘状および針状の形状を排する趣旨である。前記金属粒子の形態は、単一の球状もしくは複数の球を接合した集合体形状であり、望ましくは単一の球状であるものとする。このため、得られるナノサイズ粒子粉末はゲータイトのような紡錘状の粒子を水素で還元した粒子等に比べて流動性に優れるといった特徴も有する。よって、本発明のナノサイズ粒子はゲータイト等に比べて凝集し難く、独立分散状態が得やすいという点で有利である。比表面積が大きいので磁気ビーズ等の用途に適している。また、軟磁気特性の点でも本発明のナノサイズ粒子は優れている。 The iron-based nanosized particles of the present invention are spherical metal particles having a composition containing Fe as a main component and at least one of Co and Ni, and having a coating layer with a thickness of 1 to 200 nm. And By including Fe as a main component and containing at least one of Co and Ni, the magnetic properties can be improved, and at the same time, the corrosion resistance of the metal particles as the core can be improved. In order to maintain sufficient corrosion resistance, the lower limit of the film thickness is 1 nm or more. Furthermore, the upper limit of the film thickness is set to 200 nm in order to exhibit sufficient magnetic properties as iron-based nano-sized particles. From the viewpoint of high magnetic properties, it is more preferably 40 nm or less. The particle size of the metal particles is preferably nano-sized, that is, in the range of 1 to 1000 nm, but more preferably in the range of 10 to 1000 nm. The term “spherical” means that the spindle and needle shapes are excluded. The form of the metal particles is a single sphere or an aggregate shape formed by joining a plurality of spheres, and is preferably a single sphere. For this reason, the obtained nano-sized particle powder also has a feature that it has excellent fluidity compared to particles obtained by reducing spindle-shaped particles such as goethite with hydrogen. Therefore, the nano-sized particles of the present invention are advantageous in that they are less likely to agglomerate than goethite and the like, and an independent dispersion state is easily obtained. Because of its large specific surface area, it is suitable for applications such as magnetic beads. The nano-sized particles of the present invention are also excellent in terms of soft magnetic properties.
また、前記金属粒子は、Ｆｅと、ＣｏおよびＮｉのうちの少なくとも一種との結晶質合金であることが好ましい。Ｆｅと、ＣｏおよびＮｉのうちの少なくとも一種が結晶質合金として存在することによって磁気特性の改善が図られるほか、均質なナノサイズ粒子となる。 The metal particles are preferably a crystalline alloy of Fe and at least one of Co and Ni. The presence of at least one of Fe, Co, and Ni as a crystalline alloy improves the magnetic properties, and makes uniform nano-sized particles.
さらに、前記金属粒子は、ＦｅおよびＣｏを含み、ＣｏとＦｅの質量比Ｃｏ／Ｆｅが０．３〜０．９の範囲であることが好ましい。飽和磁化を高くするためには特にこの組成比であることが望ましい。また、前記金属粒子は、Ｆｅ、ＣｏおよびＮｉを含み、ＣｏとＦｅの質量比Ｃｏ／Ｆｅが０．３〜０．９、ＮｉとＦｅの質量比Ｎｉ／Ｆｅが０．０１〜０．５の範囲であることも磁気特性向上の観点から好ましい。 Furthermore, the metal particles preferably include Fe and Co, and the mass ratio Co / Fe of Co to Fe is in the range of 0.3 to 0.9. This composition ratio is particularly desirable in order to increase the saturation magnetization. The metal particles include Fe, Co and Ni, and the mass ratio Co / Fe of Co / Fe is 0.3 to 0.9, and the mass ratio Ni / Fe of Ni / Fe is 0.01 to 0.5. This range is also preferable from the viewpoint of improving magnetic properties.
さらに、前記金属粒子は、そのＸ線回折パターンにおける面心立方晶構造の（１１１）回折ピーク（γ−Ｆｅ相に相当）と体心立方晶構造の（１１０）回折ピーク（α−Ｆｅ相に相当）の強度比I（１１１）／I（１１０）が０．２以下であることを特徴とする。 Further, the metal particles have a (111) diffraction peak (corresponding to the γ-Fe phase) of the face-centered cubic structure and an (110) diffraction peak (α-Fe phase) of the body-centered cubic structure in the X-ray diffraction pattern. Equivalent) intensity ratio I (111) / I (110) is 0.2 or less.
また、前記金属粒子は、ＦｅおよびＮｉを含み、ＮｉとＦｅの質量比Ｎｉ／Ｆｅが０．０１〜０．１または０．４〜１５のいずれかの範囲であってもよい。 The metal particles may include Fe and Ni, and the mass ratio Ni / Fe of Ni and Fe may be in the range of 0.01 to 0.1 or 0.4 to 15.
前記被覆層はＣの被覆層またはＣを主成分とする被覆層とすることができる。 The coating layer may be a C coating layer or a coating layer containing C as a main component.
また、前記被覆層は金属元素Ｍ（金属元素Ｍは、Ａｌ、Ａｓ、Ｂ、Ｃｅ、Ｃｏ、Ｃｒ、Ｇａ、Ｈｆ、Ｉｎ、Ｍｎ、Ｎｂ、Ｔｉ、Ｖ、Ｚｒ、Ｓｃ、Ｓｉ、Ｙ、Ｔａから選ばれた一種以上）の酸化物もしくは窒化物で構成することもできる。被覆層の構成元素は、より好ましくはＡｌ、Ｂ、Ｎｂ、Ｔｉ、Ｖ、Ｚｒのいずれかとする。なお、ＡｓやＢは半金属的な元素であるが、本明細書では、酸化物もしくは窒化物を構成する元素として、ＡｓやＢも“金属元素”に包含する。 The covering layer is made of a metal element M (the metal element M is Al, As, B, Ce, Co, Cr, Ga, Hf, In, Mn, Nb, Ti, V, Zr, Sc, Si, Y, Ta 1 or more types of oxides or nitrides selected from the above. More preferably, the constituent element of the coating layer is any one of Al, B, Nb, Ti, V, and Zr. Note that As and B are semi-metallic elements, but in this specification, As and B are also included in the “metal element” as elements constituting oxides or nitrides.
また、本発明においては、被覆層に含まれる金属の元素Ｍは、酸化物の標準生成自由エネルギーが
ΔＧ(Ｆｅ,Ｃｏ,Ni)−Ｏ≧ΔＧＭ−Ｏ
という関係を満たす元素Ｍであることが好ましい。より好ましいＭ元素はＡｌ、Ｂ、Ｎｂ、Ｔｉ、Ｖ、Ｚｒである。さらに、前記被覆層は窒化硼素（ＢＮ）からなることがより望ましい。被覆層の膜厚は１〜２００ｎｍの範囲が好ましく、１ｎｍ未満では十分な耐食性が得られない。また、被覆層の膜厚が２００ｎｍ超では磁性成分である金属粒子の体積率が低下し、磁化が著しく低下する。より好ましくは１〜４０ｎｍである。
In the present invention, the metal element M included in the coating layer has a standard free energy of formation of oxide of ΔG (Fe, Co, Ni) −O ≧ ΔG M−O
It is preferable that the element M satisfies the relationship. More preferable M elements are Al, B, Nb, Ti, V, and Zr. Further, the covering layer is more preferably made of boron nitride (BN). The film thickness of the coating layer is preferably in the range of 1 to 200 nm, and if it is less than 1 nm, sufficient corrosion resistance cannot be obtained. On the other hand, when the thickness of the coating layer exceeds 200 nm, the volume fraction of the metal particles, which are magnetic components, is reduced, and the magnetization is significantly reduced. More preferably, it is 1-40 nm.
本発明の鉄系ナノサイズ粒子の製造方法は、Ｆｅを主成分としてＣｏおよびＮｉのうちの１種以上の元素を含む酸化物粉末と、Ｃを含有する粉末とを混合して混合粉末とし、前記混合粉末を非酸化性雰囲気中で熱処理することを特徴とする。該方法によって、Ｆｅを主成分としてＣｏおよびＮｉのうちの１種以上の元素を含む金属粒子をＣの被覆層もしくはＣを主成分とする被膜層で覆ったナノサイズ粒子を、極めて簡易な方法で提供することができる。 The method for producing iron-based nanosized particles of the present invention is a mixed powder obtained by mixing an oxide powder containing Fe as a main component and containing one or more elements of Co and Ni and a powder containing C. The mixed powder is heat-treated in a non-oxidizing atmosphere. By this method, nano-sized particles in which metal particles containing Fe as a main component and containing one or more elements of Co and Ni are covered with a coating layer of C or a coating layer containing C as a main component are extremely simple methods. Can be offered at.
本発明の鉄系ナノサイズ粒子の製造方法は、Ｆｅを主成分としてＣｏおよびＮｉのうちの１種以上の元素を含む酸化物粉末と、金属元素Ｍ（金属元素Ｍは、Ａｌ、Ａｓ、Ｂ、Ｃｅ、Ｃｏ、Ｃｒ、Ｇａ、Ｈｆ、Ｉｎ、Ｍｎ、Ｎｂ、Ｔｉ、Ｖ、Ｚｒ、Ｓｃ、Ｓｉ、Ｙ、Ｔａから選ばれた一種以上）を含む粉末とを混合して混合粉末とし、前記混合粉末を非酸化性雰囲気中で熱処理することを特徴とする。該方法によって、Ｆｅを主成分としてＣｏおよびＮｉのうちの１種以上の元素を含む金属粒子を金属元素Ｍの酸化物もしくは窒化物である被膜層で覆ったナノサイズ粒子を、極めて簡易な方法で提供することができる。 The method for producing iron-based nano-sized particles of the present invention includes an oxide powder containing Fe as a main component and one or more elements of Co and Ni, a metal element M (where the metal element M is Al, As, B). , Ce, Co, Cr, Ga, Hf, In, Mn, Nb, Ti, V, Zr, Sc, Si, Y, Ta), and a powder containing the mixture. The mixed powder is heat-treated in a non-oxidizing atmosphere. By this method, nano-sized particles in which metal particles containing Fe as a main component and containing one or more elements of Co and Ni are covered with a coating layer that is an oxide or nitride of a metal element M are extremely simple. Can be offered at.
本発明の鉄系ナノサイズ粒子の製造方法は、Ｆｅを主成分としてＣｏおよびＮｉのうちの１種以上の元素を含む酸化物粉末と、Ｆｅ、Ｃｏ、Ｎｉより酸化されやすい元素粉末とを混合して混合粉末とし、前記混合粉末を非酸化性雰囲気中で熱処理することを特徴とする。 The method for producing iron-based nano-sized particles according to the present invention comprises mixing an oxide powder containing Fe as a main component and containing one or more elements of Co and Ni and an element powder that is more easily oxidized than Fe, Co, and Ni. The mixed powder is heat-treated in a non-oxidizing atmosphere.
Ｆｅを主成分としてＣｏおよびＮｉのうちの少なくとも一種以上を含む組成を有する球状の金属粒子の表面に、膜厚が１〜２００ｎｍの範囲内である被覆層を有する本発明の鉄系ナノサイズ粒子により、優れた磁気特性と、優れた耐酸化性を得ることができる。本発明に係る製造方法により、表面が耐酸化性被膜で被覆された、凝集しにくいナノサイズ粒子を製造することができる。 The iron-based nanosized particles of the present invention having a coating layer having a film thickness in the range of 1 to 200 nm on the surface of spherical metal particles having a composition containing Fe as a main component and containing at least one of Co and Ni Thus, excellent magnetic properties and excellent oxidation resistance can be obtained. By the production method according to the present invention, nano-sized particles which are coated with an oxidation resistant film and hardly aggregate can be produced.
本発明において、金属粒子はＦｅを主成分としてＣｏおよびＮｉのうちの少なくとも一種以上を含む組成の粒子である。前記金属粒子の粒径は、例えば１〜１０００ｎｍの範囲内とすることができるが、特に１０〜１０００ｎｍの範囲が好ましい。１ｎｍ未満のものは製造上粒径制御が困難である他、１０ｎｍ未満であると超常磁性の発現により磁化が低下してしまい好ましくなく、１０００ｎｍを超えると金属粒子を前記被覆層が完全に被覆することが出来なくなり耐蝕性を維持できなくなるので好ましくない。１０〜１０００ｎｍの範囲において、本発明の合金化によるγ相低減、磁気特性向上の効果が顕著になる。なお、ここでいう粒径は金属粒子の核の部分の粒径である。また、Ｆｅと、ＣｏおよびＮｉのうちの少なくとも一種は、結晶質合金として存在する。これによって磁気特性の向上が図られるとともに均質なナノサイズ粒子を得ることができる。さらにＦｅを主成分としてＣｏおよびＮｉのうちの少なくとも一種以上を含んでいることにより、熱処理工程における当該金属粒子の粒成長を抑制することができ、同時に耐蝕性を向上させることができる。すなわちＣｏおよびＮｉのうちの少なくとも一種以上を含むことにより粗大粒子の生成を抑制し、なおかつたとえ前記被覆層が不十分であったとしても酸化による磁気特性の劣化を抑制することができる。ＣｏおよびＮｉの含有量は、最終的に鉄系ナノサイズ粒子とした時に、ＣｏがＦｅに対する質量比で０．3〜０．９の範囲内にあり、ＮｉがＦｅに対する質量比で０．０１〜０．５の範囲内にあることが好ましい。これにより、磁気特性として、例えば飽和磁化が１２０Ａｍ２／ｋｇ以上を得ることも可能となる。Ｆｅ−Ｃｏの２元系組成は、鉄系ナノサイズ粒子が例えば磁気記録媒体や磁気ビーズに使用される場合に適用することが好ましい。この２元系組成においては、ＦｅにＣｏを添加して合金化させることにより、α相から高温相であるγ相への転移温度が上昇してα相が安定化するため、γ−Ｆｅ相の析出を抑制することができる。ＣｏのＦｅに対する質量比が０．３未満の場合はＣｏの添加効果が期待できず、０．９を越える場合は飽和磁化が１２０Ａｍ２／ｋｇ未満となる。上記好適範囲のＣｏを含むことによりγ相の析出を抑制でき、Ｘ線回折パターンにおいて面心立方晶構造の（１１１）回折ピーク（γ相に相当する）と体心立方晶構造の（１１０）回折ピーク（α相に相当する）の強度比I（１１１）／I（１１０）が０．２以下となり、高い飽和磁化が得られる。また、Ｆｅ−Ｃｏ−Ｎｉの３元系組成においても上記と同様の効果が期待されるが、軟磁気特性に優れるという特徴があり、高い飽和磁化と低い磁歪を有する材料が得られる。そして、Ｎｉの添加量が質量比で０．０１未満では磁歪が大きく、Ｎｉの添加量が質量比で０．５超では飽和磁化が１２０Ａｍ２／ｋｇ未満となる。 In the present invention, the metal particles are particles having a composition containing Fe as a main component and containing at least one of Co and Ni. The particle size of the metal particles can be, for example, in the range of 1 to 1000 nm, and particularly preferably in the range of 10 to 1000 nm. If the particle size is less than 1 nm, it is difficult to control the particle size, and if it is less than 10 nm, magnetization is reduced due to the appearance of superparamagnetism, and if it exceeds 1000 nm, the coating layer completely covers the metal particles. It is not preferable because the corrosion resistance cannot be maintained. In the range of 10 to 1000 nm, the effects of reducing the γ phase and improving the magnetic properties by the alloying of the present invention become remarkable. The particle size referred to here is the particle size of the core part of the metal particles. Further, at least one of Fe, Co, and Ni exists as a crystalline alloy. As a result, the magnetic properties are improved and uniform nano-sized particles can be obtained. Further, by containing at least one of Co and Ni with Fe as a main component, grain growth of the metal particles in the heat treatment step can be suppressed, and at the same time, corrosion resistance can be improved. That is, by containing at least one or more of Co and Ni, generation of coarse particles can be suppressed, and deterioration of magnetic properties due to oxidation can be suppressed even if the coating layer is insufficient. The content of Co and Ni is, when finally made into iron-based nanosized particles, Co is in the range of 0.3 to 0.9 by mass ratio to Fe, and Ni is 0.01 mass ratio to Fe. It is preferable that it exists in the range of -0.5. Thereby, as a magnetic characteristic, for example, it becomes possible to obtain a saturation magnetization of 120 Am 2 / kg or more. The binary composition of Fe—Co is preferably applied when iron-based nano-sized particles are used, for example, in magnetic recording media and magnetic beads. In this binary composition, by adding Co to Fe and alloying, the transition temperature from the α phase to the γ phase, which is a high temperature phase, is increased and the α phase is stabilized, so the γ-Fe phase Precipitation can be suppressed. When the mass ratio of Co to Fe is less than 0.3, the effect of adding Co cannot be expected, and when it exceeds 0.9, the saturation magnetization is less than 120 Am 2 / kg. Precipitation of the γ phase can be suppressed by containing Co in the above preferred range, and the (111) diffraction peak (corresponding to the γ phase) of the face-centered cubic structure and the (110) of the body-centered cubic structure in the X-ray diffraction pattern. The intensity ratio I (111) / I (110) of the diffraction peak (corresponding to the α phase) is 0.2 or less, and high saturation magnetization is obtained. The same effect as described above is also expected in the Fe-Co-Ni ternary composition, but it is characterized by excellent soft magnetic properties, and a material having high saturation magnetization and low magnetostriction can be obtained. When the addition amount of Ni is less than 0.01 by mass ratio, the magnetostriction is large, and when the addition amount of Ni exceeds 0.5 by mass ratio, the saturation magnetization is less than 120 Am 2 / kg.
また、ＦｅにＮｉを添加して合金化させることにより、軟磁気特性が改善され低保磁力・高透磁率が発現する。軟磁気特性の改善は、磁化が飽和しやすいことを意味する。すなわち、軟磁気特性が改善された粒子では高透磁率であるが故に、特に０．３Ｔ以下の低磁界を印加した場合でも高磁化を示し、磁界に対する粒子の反応性が良くなる。また、ＦｅとＮｉを合金化させることにより、耐食性の向上にも寄与する。さらに熱力学的考察によればＮｉ酸化物はＦｅ酸化物よりも容易に還元されるため、製造上、より低い温度での熱処理を可能にする。ＮｉのＦｅに対する質量比は０．０１〜０．１または０．４〜１５のいずれかの範囲であることが好ましい。Ｎｉを含有することで低保磁力・高透磁率が発現して軟磁気特性が改善されるが、ＮｉのＦｅに対する質量比が該範囲を外れると飽和磁化が４０Ａｍ２／ｋｇ未満まで低下し、フェライトで代表される酸化物磁性材料との優位差が消失してしまうので好ましくない。 Further, by adding Ni to Fe and alloying, soft magnetic characteristics are improved and low coercivity and high magnetic permeability are exhibited. An improvement in soft magnetic characteristics means that magnetization is likely to be saturated. That is, since particles having improved soft magnetic properties have high magnetic permeability, high magnetization is exhibited even when a low magnetic field of 0.3 T or less is applied, and the reactivity of the particles to the magnetic field is improved. In addition, alloying Fe and Ni contributes to the improvement of corrosion resistance. Further, according to thermodynamic considerations, Ni oxides are more easily reduced than Fe oxides, so that heat treatment at a lower temperature is possible in production. The mass ratio of Ni to Fe is preferably in the range of 0.01 to 0.1 or 0.4 to 15. By containing Ni, low coercive force and high magnetic permeability are developed and soft magnetic properties are improved. However, when the mass ratio of Ni to Fe is out of the range, the saturation magnetization decreases to less than 40 Am 2 / kg, This is not preferable because the dominant difference from the oxide magnetic material represented by ferrite disappears.
上記の金属粒子は、製造上混入し得る不純物もしくは原料由来の不可避的不純物であるＣ、Ｎ、Ｏのうちの一種以上の元素を１０〜１０００００ｐｐｍの範囲で含有することができる。不純物量が１０ｐｐｍ未満では表面が活性なため、発火しやすく、１０００００ｐｐｍ超では飽和磁化が１２０Ａｍ２／ｋｇ未満となってしまう。ｐｐｍは、粉末の単位質量当たりの不純物含有量を質量百万分率で表した単位に相当する。 Said metal particle can contain in the range of 10-100,000 ppm of 1 or more elements of C, N, and O which are the impurities which can mix in manufacture or the inevitable impurities derived from a raw material. If the amount of impurities is less than 10 ppm, the surface is active, and therefore it is easy to ignite, and if it exceeds 100000 ppm, the saturation magnetization is less than 120 Am 2 / kg. ppm corresponds to a unit expressed by mass parts per million of the impurity content per unit mass of the powder.
本発明においては、例えば次のようにして、上記金属粒子の表面に被覆層（好ましくは耐酸化性被覆）を形成することができる。まず、上記金属粒子の主成分であるＦｅ，ＣｏおよびＮｉを含む酸化物粉末を準備する。この酸化物粉末の粒径は、目標とする鉄系ナノサイズ粒子の粒径に応じて選択することができるが、実用的には１０〜１００００ｎｍの範囲が好適である。Ｆｅ，ＣｏおよびＮｉを含む酸化物粉末としては、Ｆｅの酸化物とＣｏもしくはＮｉの酸化物粉末との混合粉末であっても良いし、ＦｅとＣｏと酸素を含んだ化合物粉末或いはＦｅとＮｉと酸素を含んだ化合物粉末であっても良い。あるいは上記酸化物粉末とＦｅとＣｏと酸素を含んだ粉末の混合粉末であっても良い。Ｆｅの酸化物粉末としては、例えばＦｅ２Ｏ３、Ｆｅ３Ｏ４、ＦｅＯが挙げられ、Ｃｏの酸化物としては、例えばＣｏ２Ｏ３、Ｃｏ３Ｏ４が挙げられ、Ｎｉの酸化物としては、例えばＮｉＯが挙げられる。ＦｅとＣｏと酸素を含んだ化合物としては、例えばＣｏＦｅ２Ｏ４が挙げられ、ＦｅとＮｉと酸素を含んだ化合物としては例えばＮｉＦｅ２Ｏ４などが挙げられる。 In the present invention, for example, a coating layer (preferably an oxidation resistant coating) can be formed on the surface of the metal particles as follows. First, an oxide powder containing Fe, Co, and Ni, which are the main components of the metal particles, is prepared. The particle size of the oxide powder can be selected according to the target particle size of the iron-based nano-sized particles, but a range of 10 to 10,000 nm is suitable for practical use. The oxide powder containing Fe, Co and Ni may be a mixed powder of an oxide of Fe and Co or Ni, or a compound powder containing Fe, Co and oxygen, or Fe and Ni. And a compound powder containing oxygen. Alternatively, a mixed powder of the oxide powder, a powder containing Fe, Co, and oxygen may be used. Examples of the Fe oxide powder include Fe 2 O 3 , Fe 3 O 4 , and FeO. Examples of the Co oxide include Co 2 O 3 and Co 3 O 4 , and examples of the Ni oxide include Is, for example, NiO. Examples of the compound containing Fe, Co, and oxygen include CoFe 2 O 4. Examples of the compound containing Fe, Ni, and oxygen include NiFe 2 O 4 .
次に、上記金属粒子の表面に、Ｃの被覆層もしくはＣを主成分とする被膜層、ならびにＡｌ、Ａｓ、Ｂ、Ｃｅ、Ｃｏ、Ｃｒ、Ｇａ、Ｈｆ、Ｉｎ、Ｍｎ、Ｎｂ、Ｔｉ、Ｖ、Ｚｒ、Ｓｃ、Ｓｉ、Ｙ、Ｔａから選ばれた一種以上の金属元素（Ｍ元素）の酸化物もしくは窒化物の被覆層が形成される。被覆層として、本発明では金属のＭ元素の酸化物もしくは窒化物が望ましい。上記の金属のＭ元素は、酸化物の標準生成自由エネルギーが数１という関係を満足するので、Ｆｅ，ＣｏおよびＮｉを含む酸化物を還元することができる。 Next, on the surface of the metal particles, a coating layer of C or a coating layer containing C as a main component, and Al, As, B, Ce, Co, Cr, Ga, Hf, In, Mn, Nb, Ti, V A coating layer of oxide or nitride of at least one metal element (M element) selected from Zr, Sc, Si, Y, and Ta is formed. As the coating layer, an oxide or nitride of metal M element is desirable in the present invention. Since the M element of the metal satisfies the relationship that the standard free energy of formation of the oxide satisfies the formula 1, the oxide containing Fe, Co, and Ni can be reduced.
ここで、ΔＧ(Ｆｅ,Ｃｏ,Ni)−Ｏは化学反応式である数２に示すようにＦｅ、ＣｏおよびＮｉが酸素と反応し、その酸化物を形成する反応の標準生成自由エネルギーである。 Here, ΔG (Fe, Co, Ni) -O is the standard free energy of formation for the reaction in which Fe, Co, and Ni react with oxygen to form an oxide as shown in the chemical reaction equation ( 2 ). .
ここで、ΔＧＭ−Ｏは金属のＭ元素が酸素と反応し、酸化物を形成する反応の標準生成自由エネルギーであり、Ｍ元素はＦｅ，ＣｏおよびＮｉより酸化されやすい元素と定義される。 Here, ΔG M-O is a standard free energy of formation for a reaction in which an M element of a metal reacts with oxygen to form an oxide, and the M element is defined as an element that is more easily oxidized than Fe, Co, and Ni.
例えば、Ｆｅの酸化物としてＦｅ２Ｏ３を考えた場合、ΔＧＦｅ２Ｏ３＝−７４０ｋＪ／ｍｏｌよりも小さいΔＧＭ−Ｏを有する酸化物は、Ａｌ２Ｏ３、Ａｓ２Ｏ５、Ｂ２Ｏ３、ＣｅＯ２、Ｃｅ２Ｏ３、Ｃｏ３Ｏ４、Ｃｒ２Ｏ３、Ｇａ２Ｏ３、ＨｆＯ２、Ｉｎ２Ｏ３、Ｍｎ２Ｏ３、Ｍｎ３Ｏ４、Ｎｂ２Ｏ５、ＴｉＯ２、Ｔｉ２Ｏ３、Ｔｉ３Ｏ５、Ｖ２Ｏ３、Ｖ２Ｏ５、Ｖ３Ｏ５、ＺｒＯ２、Ｓｃ２Ｏ３、Ｙ２Ｏ３、Ｔａ２Ｏ５、あるいは各種の希土類元素の酸化物等が挙げられる。 For example, when considering the Fe 2 O 3 as an oxide of Fe, ΔG Fe2O3 = -740kJ / mol oxide having a small .DELTA.G M-O than is, Al 2 O 3, As 2 O 5, B 2 O 3 , CeO 2, Ce 2 O 3 , Co 3 O 4, Cr 2 O 3, Ga 2 O 3, HfO 2, In 2 O 3, Mn 2 O 3, Mn 3 O 4, Nb 2 O 5, TiO 2, Oxidation of Ti 2 O 3 , Ti 3 O 5 , V 2 O 3 , V 2 O 5 , V 3 O 5 , ZrO 2 , Sc 2 O 3 , Y 2 O 3 , Ta 2 O 5 , or various rare earth elements Thing etc. are mentioned.
なお、Ｍ元素を含む粉末は、Ｍ元素単体であっても構わないが、炭化物（Ｍ−Ｃ）、ほう化物（Ｍ−Ｂ）、窒化物（Ｍ−Ｎ）であっても構わない。Ｍ元素としてはＢを選択し、非酸化性雰囲気として窒素ガス（Ｎ２）を用いた場合に、最も良い結果が得られる。この場合、被覆層として窒化ほう素（ＢＮ）が形成され、本発明の鉄系ナノサイズ粒子に優れた耐酸化性が付与される。特に、ＢＮは潤滑性に優れるため、ナノサイズ粒子が凝集することなく、個々のナノサイズ粒子が独立分散した状態を形成しやすくなるといった利点を有する。また、ＣもＦｅ，ＣｏおよびＮｉを含む酸化物を還元することができる。したがって、Ｍ元素を含む粉末と同様、Ｃを含有する粉末も用いることができる。Ｍ元素を含有する金属粉末、Ｃを含有する粉末の粒径は１〜１００００ｎｍの範囲内にあることが好ましく、還元反応をさらに効率的に行なうためには１ｎｍ〜１０００ｎｍの範囲内がより好ましい。なお、ＢやＡｓは半金属的な元素であるが、ここでは金属元素と呼ぶことにする。 In addition, although the powder containing M element may be M element single-piece | unit, it may be a carbide | carbonized_material (MC), a boride (MB), and nitride (MN). The best results are obtained when B is selected as the M element and nitrogen gas (N 2 ) is used as the non-oxidizing atmosphere. In this case, boron nitride (BN) is formed as the coating layer, and excellent oxidation resistance is imparted to the iron-based nanosized particles of the present invention. In particular, since BN is excellent in lubricity, it has an advantage that it becomes easy to form a state in which individual nano-sized particles are dispersed independently without aggregation of the nano-sized particles. C can also reduce oxides containing Fe, Co and Ni. Therefore, the powder containing C can also be used like the powder containing M element. The particle size of the metal powder containing element M and the powder containing C is preferably in the range of 1 to 10,000 nm, and more preferably in the range of 1 nm to 1000 nm in order to perform the reduction reaction more efficiently. Note that although B and As are semi-metallic elements, they are referred to as metal elements here.
上記Ｍ元素を含む被覆層やＣの被覆層もしくはＣを主成分とする被膜層は、例えばＦｅ，ＣｏおよびＮｉを含む酸化物粉末と、Ｍ元素（Ｍは、Ａｌ、Ａｓ、Ｂ、Ｃｅ、Ｃｏ、Ｃｒ、Ｇａ、Ｈｆ、Ｉｎ、Ｍｎ、Ｎｂ、Ｔｉ、Ｖ、Ｚｒ、Ｓｃ、Ｓｉ、Ｙ、Ｔａから選ばれる一種以上）を含む粉末或いはＣを含有する粉末とを混合した後、非酸化性雰囲気中で熱処理することにより、形成することができる。混合は、乳鉢、スターラー、Ｖ字型ミキサー、ボールミル、振動ミル、その他の攪拌機により行うことができる。混合は、乾式混合でも可能であるが、粉末の凝集を回避し、より均一に混合するには有機溶媒や水を用いた湿式混合が好ましい。 The coating layer containing M element, the coating layer of C, or the coating layer containing C as a main component includes, for example, an oxide powder containing Fe, Co, and Ni, and M element (M is Al, As, B, Ce, Non-oxidized after mixing with a powder containing one or more selected from Co, Cr, Ga, Hf, In, Mn, Nb, Ti, V, Zr, Sc, Si, Y, Ta or a powder containing C It can be formed by heat treatment in a neutral atmosphere. Mixing can be performed with a mortar, stirrer, V-shaped mixer, ball mill, vibration mill, or other stirrer. The mixing can be performed by dry mixing, but wet mixing using an organic solvent or water is preferable in order to avoid agglomeration of the powder and to mix more uniformly.
Ｆｅ、ＣｏおよびＮｉを含む酸化物粉末と、Ｍ元素（Ｍは、Ａｌ、Ａｓ、Ｂ、Ｃｅ、Ｃｏ、Ｃｒ、Ｇａ、Ｈｆ、Ｉｎ、Ｍｎ、Ｎｂ、Ｔｉ、Ｖ、Ｚｒ、Ｓｃ、Ｓｉ、Ｙ、Ｔａから選ばれる一種以上）を含む粉末等との混合比は、Ｆｅ、ＣｏおよびＮｉの酸化物を還元するに足る化学量論比の近傍とすることが好ましい。より好ましくはＭ元素を含む粉末等が上記化学量論比よりも過剰となることが好ましい。Ｍ元素を含む粉末等が不足すると、熱処理中にＦｅ、ＣｏおよびＮｉを含む酸化物が十分に還元されず、還元されたＦｅ、ＣｏおよびＮｉの粒子が焼結してしまい、最終的にバルク化してしまうので不都合である。 Oxide powder containing Fe, Co and Ni, and M element (M is Al, As, B, Ce, Co, Cr, Ga, Hf, In, Mn, Nb, Ti, V, Zr, Sc, Si, The mixing ratio with the powder containing at least one selected from Y and Ta is preferably close to the stoichiometric ratio sufficient to reduce the oxides of Fe, Co, and Ni. More preferably, the powder containing M element or the like is more excessive than the stoichiometric ratio. If the powder containing M element is insufficient, the oxide containing Fe, Co and Ni is not sufficiently reduced during the heat treatment, and the reduced Fe, Co and Ni particles are sintered, and finally bulk. This is inconvenient.
熱処理は、例えばＡｒ、Ｈｅなどの不活性ガスやＨ２、Ｎ２、ＣＯ２、ＮＨ３の単独もしくは１種以上の混合ガスなどを使用して、非酸化性雰囲気中で行うことが好ましい。また、熱処理温度および時間は還元反応が十分進行するに足る条件であることが好ましい。本発明の製造方法により、Ｆｅと、ＣｏおよびＮｉのうちの少なくとも一種との結晶質合金を被覆したナノサイズ粒子を極めて簡易な方法で提供することができる。 The heat treatment is preferably performed in a non-oxidizing atmosphere using, for example, an inert gas such as Ar or He, H 2 , N 2 , CO 2 , or NH 3 alone or one or more mixed gases. The heat treatment temperature and time are preferably conditions sufficient for the reduction reaction to proceed sufficiently. According to the production method of the present invention, nano-sized particles coated with a crystalline alloy of Fe and at least one of Co and Ni can be provided by a very simple method.
単位ｍａｓｓ％は、例えば、ボールミル混合した粉の単位質量当たりに含有される各々の原料粉の質量を質量百分率で表わした単位である。ｐｐｍは、例えば、実施例で得た粉末の単位質量当たりに含有されるガス元素の質量を質量百万分率で表わした単位である。 The unit mass% is, for example, a unit expressing the mass of each raw material powder contained per unit mass of the powder mixed with the ball mill as a mass percentage. ppm is the unit which expressed the mass of the gas element contained per unit mass of the powder obtained in the Example in mass parts per million.
得られた鉄系ナノサイズ粒子の平均粒径は、次に説明する第１の測定方法または第２の測定方法で算定する。第１の測定方法は、例えば微粒子の粉末を試料として、透過電子顕微鏡または走査電子顕微鏡で写真を撮影して測定するものとした。写真内で任意の微粒子について各々の直径を測定する。すなわち、Ｎ個の微粒子について（Ｎ≧５０個）、直径を測定し、平均直径＝（測定した直径の総和）／Ｎとして表わす。写真に代えて、電子的なイメージを取得し、パソコンと画像処理ソフトを利用して直径を測定してもよい。さらに、個々の微粒子の粒径（直径）とは、例えば被覆層を有する微粒子の外径に相当するが、断面が円形でない場合には最大長さと最小長さの平均値をその微粒子の粒径と見なす。核である金属粒子部分の粒径も前記方法で測定することができる。第２の測定方法は、Ｘ線回折を測定し、回折パターンにおいて例えばα-Ｆｅの（１１０）ピークの半値幅より、平均粒径を算定する。第２の測定方法は、粒径が１００ｎｍ以下である場合に、便宜的に粒径を測定する場合に使用する。この場合得られる粒径は、核である金属粒子部分の粒径に相当する。 The average particle size of the obtained iron-based nanosized particles is calculated by the first measurement method or the second measurement method described below. In the first measurement method, for example, a fine particle powder was used as a sample and a photograph was taken with a transmission electron microscope or a scanning electron microscope. Measure the diameter of each microparticle in the photograph. That is, for N fine particles (N ≧ 50 particles), the diameter is measured and expressed as average diameter = (total of measured diameters) / N. Instead of a photograph, an electronic image may be acquired and the diameter may be measured using a personal computer and image processing software. Further, the particle diameter (diameter) of each fine particle corresponds to, for example, the outer diameter of the fine particle having a coating layer, but when the cross section is not circular, the average value of the maximum length and the minimum length is the particle diameter of the fine particle. Is considered. The particle diameter of the metal particle portion which is a nucleus can also be measured by the above method. In the second measurement method, X-ray diffraction is measured, and the average particle diameter is calculated from the half width of the (110) peak of α-Fe in the diffraction pattern, for example. The second measuring method is used when the particle diameter is measured for convenience when the particle diameter is 100 nm or less. The particle size obtained in this case corresponds to the particle size of the metal particle part which is the nucleus.
被覆層の膜厚は、金属粒子の表面の所定の箇所から、被覆層の表面で最も近い箇所の距離を、前記所定の箇所における被覆層の膜厚と見なすことができる。本発明において、１０個以上の粒子について各々の粒子の膜厚を測定しその平均値を膜厚とした。各々の粒子の膜厚は、その粒子の膜の厚さを４箇所以上計測し、平均値をその粒子の膜厚とした。 Regarding the film thickness of the coating layer, the distance from the predetermined location on the surface of the metal particle to the closest location on the surface of the coating layer can be regarded as the thickness of the coating layer at the predetermined location. In the present invention, the film thickness of each particle was measured for 10 or more particles, and the average value was taken as the film thickness. As for the film thickness of each particle, the film thickness of the particle was measured at four or more locations, and the average value was defined as the film thickness of the particle.
次に本発明を実施例によって具体的に説明するが、これら実施例により本発明が必ずしも限定されるものではない。 EXAMPLES Next, although an Example demonstrates this invention concretely, this invention is not necessarily limited by these Examples.
（実施例１〜４）
平均粒径０．０３μｍのα−Ｆｅ２Ｏ３粉と平均粒径０．６μｍのＣｏ３Ｏ４粉とを所定の配合比（表１参照）となるよう秤量し、さらに平均粒径０．０２μｍのカーボンブラック粉が３０ｍａｓｓ％となるように加えてボールミル混合機にて１６時間乾式混合した。得られた混合粉をアルミナボートに適量充填し、純度９９．９％以上の窒素ガスを用いて雰囲気酸素量を１０ｐｐｍ以下に制御し、１０００℃×２時間の熱処理を行なった。加熱処理終了後に室温まで冷却した後にアルミナボートを取り出し、熱処理された試料粉末を回収した。
(Examples 1-4)
Α-Fe 2 O 3 powder having an average particle diameter of 0.03 μm and Co 3 O 4 powder having an average particle diameter of 0.6 μm are weighed so as to have a predetermined mixing ratio (see Table 1). 02 μm carbon black powder was added to 30 mass% and dry-mixed for 16 hours in a ball mill mixer. An appropriate amount of the obtained mixed powder was filled into an alumina boat, and the amount of atmospheric oxygen was controlled to 10 ppm or less using nitrogen gas having a purity of 99.9% or more, and heat treatment was performed at 1000 ° C. for 2 hours. After the heat treatment, the alumina boat was taken out after cooling to room temperature, and the heat-treated sample powder was collected.
なお、配合前の原料の平均粒径は、透過電子顕微鏡写真を撮影して測定した。写真内で任意の微粒子について各々の直径を測定して６０個の平均値を求めた。 The average particle size of the raw material before blending was measured by taking a transmission electron micrograph. The average value of 60 particles was determined by measuring the diameter of each fine particle in the photograph.
上記試料粉末についてＸ線回折測定を行った。リガク製ＲＩＮＴ２５００を用いて、測定はθ／２θスキャンで２θ＝４０°〜５０°の範囲で行った。面心立方晶構造（ｆｃｃ）の（１１１）ピークと体心立方晶構造（ｂｃｃ）の（１１０）ピーク強度を求めた。得られたＸ線回折パターンを図１に示す。図１の横軸は回折角の２θ（°）であり、縦軸は回折パターンの相対的な強度に相当する。ただし、回折パターン同士が重なっていると見え難いので、カーブの強度の基準を任意にずらして図示した。ＭＤＩ社製解析ソフト「Ｊａｄｅ，ｖｅｒ．５」を用いて解析を行い、各回折ピーク強度の比（Ｉ（１１１）／Ｉ（１１０））、及び（１１０）ピークの半値幅より便宜的に求めた平均粒径を表２にまとめた。また、上記試料粉末の磁気特性をいわゆるＶＳＭ：振動試料磁束計（東英工業社製ＶＳＭ−５型）にて印加磁界が±２Ｔの範囲で測定した結果を表２に示す。 X-ray diffraction measurement was performed on the sample powder. Using RINT 2500 manufactured by Rigaku, measurement was performed in the range of 2θ = 40 ° to 50 ° by θ / 2θ scan. The (111) peak of the face-centered cubic structure (fcc) and the (110) peak intensity of the body-centered cubic structure (bcc) were determined. The obtained X-ray diffraction pattern is shown in FIG. The horizontal axis in FIG. 1 is 2θ (°) of the diffraction angle, and the vertical axis corresponds to the relative intensity of the diffraction pattern. However, since it is difficult to see if the diffraction patterns overlap each other, the curve intensity reference is arbitrarily shifted. The analysis is performed using analysis software “Jade, ver. 5” manufactured by MDI, and is conveniently obtained from the ratio of each diffraction peak intensity (I (111) / I (110)) and the half width of the (110) peak. The average particle diameters are summarized in Table 2. Table 2 shows the magnetic properties of the sample powder measured with a so-called VSM: vibrating sample magnetometer (VSM-5 manufactured by Toei Kogyo Co., Ltd.) in the range of ± 2T applied magnetic field.
（比較例１）
平均粒径０．０３μｍのα−Ｆｅ２Ｏ３粉を７０ｍａｓｓ％、平均粒径０．０２μｍのカーボンブラック粉を３０ｍａｓｓ％とした以外は実施例と同様の製造方法で試料粉末を作製した。Ｘ線回折パターンを図１に示し、各特性を表２に示す。
(Comparative Example 1)
A sample powder was produced by the same production method as in the example except that α-Fe 2 O 3 powder having an average particle size of 0.03 μm was changed to 70 mass% and carbon black powder having an average particle size of 0.02 μm was changed to 30 mass%. The X-ray diffraction pattern is shown in FIG. 1, and each characteristic is shown in Table 2.
（比較例２）
平均粒径０．６μｍのＣｏ３Ｏ４粉を７０ｍａｓｓ％、平均粒径０．０２μｍのカーボンブラック粉を３０ｍａｓｓ％とした以外は実施例１〜４と同様の原料（表１参照）と製造方法で試料粉末を作製した。Ｘ線回折パターンを測定したところ、この比較例２の試料は面心立方構造を示した。試料の各特性を表２に示す。なお、試料を構成するナノサイズ粒子の平均粒径は（１１１）ピークから求めた。
(Comparative Example 2)
The same raw materials (see Table 1) and production method as in Examples 1 to 4 except that Co 3 O 4 powder with an average particle size of 0.6 μm was 70 mass% and carbon black powder with an average particle size of 0.02 μm was 30 mass%. A sample powder was prepared. When the X-ray diffraction pattern was measured, the sample of Comparative Example 2 showed a face-centered cubic structure. Table 2 shows the characteristics of the sample. In addition, the average particle diameter of the nanosize particle which comprises a sample was calculated | required from the (111) peak.
表２から、実施例１〜４によれば、比較例と比較すると、Ｉ（１１１）／Ｉ（１１０）は０．２以下と小さく、Ｃｏ添加によりγ相の析出が抑制されていることが分かった。また飽和磁化は１２０Ａｍ２／ｋｇ以上の高い値を示した。実際、Ｃｏ／Ｆｅ質量比が０.３〜０.８２では１３０Ａｍ２／ｋｇ以上の高い飽和磁化を示した。すなわち、Ｃｏの添加によって強磁性を示すα相の体積率が増加した上、さらにＦｅＣｏ合金化したことにより、飽和磁化が向上した。さらに、粉末を構成するナノサイズ粒子の平均粒径は比較例よりも小さく、体心立方晶構造（α相）の微細な粒子が得られることが分かった。 From Table 2, according to Examples 1-4, compared with a comparative example, I (111) / I (110) is as small as 0.2 or less, and precipitation of (gamma) phase is suppressed by Co addition. I understood. The saturation magnetization showed a high value of 120 Am 2 / kg or more. In fact, when the Co / Fe mass ratio was 0.3 to 0.82, a high saturation magnetization of 130 Am 2 / kg or more was exhibited. That is, the addition of Co increased the volume fraction of the α phase exhibiting ferromagnetism, and further increased the saturation magnetization by forming an FeCo alloy. Furthermore, it was found that the average particle size of the nano-sized particles constituting the powder was smaller than that of the comparative example, and fine particles having a body-centered cubic structure (α phase) were obtained.
実施例３の試料粉末について透過型電子顕微鏡（ＴＥＭ）で観察したところ、図２の電子顕微鏡写真に示すようにＦｅＣｏ粒子１はＣ膜３で被覆されていることがわかった。Ｃ膜３に見える円環模様２は干渉による縞模様に相当する。他のＦｅＣｏ粒子５もＣ膜６で被覆されていた。ＦｅＣｏ粒子１，５はほぼ球形である。他の被覆粒子１０，１１も、写真の外にはみ出した部分において、ＦｅＣｏ粒子を被覆している様子を観察することができた。Ｃ膜６の一部がＣ膜３に重なっているように見えるが、Ｃ膜６が途中で切れているわけではなく、Ｃ膜６はＦｅＣｏ粒子５の周囲を隙間無く覆っていることがわかった。図３は、図２の写真の概要を模写した模式図である。図２と図３の枠はほぼ同寸法である。図３の右下に記入した“５０ｎｍ”という表示に並べて記載した横棒は、その長さが５０ｎｍを表わすスケールに相当する。このスケールを基にして図２の粒子や被覆の寸法が分かる。例えば、Ｃ膜６は、およそ１５ｎｍ前後の厚さの被膜となっていた。 When the sample powder of Example 3 was observed with a transmission electron microscope (TEM), it was found that the FeCo particles 1 were covered with the C film 3 as shown in the electron micrograph of FIG. The circular pattern 2 visible on the C film 3 corresponds to a striped pattern due to interference. Other FeCo particles 5 were also covered with the C film 6. The FeCo particles 1 and 5 are substantially spherical. It was possible to observe that the other coated particles 10 and 11 were coated with FeCo particles in a portion protruding from the photograph. Although it seems that a part of the C film 6 overlaps the C film 3, the C film 6 is not cut off in the middle, and the C film 6 covers the periphery of the FeCo particles 5 without any gaps. It was. FIG. 3 is a schematic diagram in which the outline of the photograph of FIG. 2 is copied. 2 and 3 have substantially the same dimensions. The horizontal bar written side by side on the display “50 nm” written in the lower right of FIG. 3 corresponds to a scale whose length represents 50 nm. Based on this scale, the particle and coating dimensions of FIG. For example, the C film 6 is a film having a thickness of about 15 nm.
（実施例５）
平均粒径０．０３μｍのα−Ｆｅ２Ｏ３粉と平均粒径０．６μｍのＣｏ3Ｏ4粉と平均粒径３μｍの粉を、α−Ｆｅ２Ｏ３粉：４５ｍａｓｓ％、Ｃｏ3Ｏ4粉：２５ｍａｓｓ％、Ａｌ粉：３０ｍａｓｓ％となるよう秤量してボールミル混合機にて５時間湿式混合した。溶媒にはＩＰＡ（イソプロピルアルコール）を用いた。得られた混合粉を乾燥後、アルミナボートに適量充填し、純度９９．９％以上の窒素ガス中にて１０００℃×２時間の熱処理を行なった。室温まで冷却した後にアルミナボートを取り出したところ、熱処理直後の試料粉は凝集していたため、乳鉢で解砕した。得られた試料粉についてX線回折測定を行い、ｂｃｃ構造の（１１０）ピークの半値幅より便宜的に求めた平均粒子径を表３に示す。なお、X線回折パターンにはｂｃｃ構造のピーク（ＦｅＣｏ合金に相当）の他にアルミナ（α−Ａｌ２Ｏ３）に相当するピークが得られた。余分なアルミナ粒子を除去するため、次に述べる磁気分離操作を２０回実施した。すなわち、IPA中に所定量の試料粉を投入して超音波を１０分間印加し、次いで永久磁石で磁性粒子だけ吸着させて上澄み液を除去する磁気分離操作である。磁気分離後の試料粉の磁気特性をＶＳＭで測定した結果を表３に示す。使用したＶＳＭ：振動試料磁束計（東英工業社製ＶＳＭ−５型）において、印加磁界は±２Ｔで測定した。被覆層のアルミナが含まれていることによりFeの体積率が減少し、飽和磁化はFe理論値の８０％程度となっている。また、本試料の耐蝕性を評価するため、磁気分離後の試料粉２５ｍｇをｐH：１１のアンモニア水１ｍｌ中に９６時間浸漬させ、液中に溶出したFeおよびCoイオン濃度を測定した。結果を表３に示す。ＦｅおよびCoの溶出量は、０．５ｐｐｍ以下となり、溶出量の少ない耐食性の良好な粒子が得られた。
(Example 5)
An α-Fe 2 O 3 powder with an average particle size of 0.03 μm, a Co 3 O 4 powder with an average particle size of 0.6 μm, and a powder with an average particle size of 3 μm are mixed into an α-Fe 2 O 3 powder: 45 mass%, Co 3 O 4 powders: 25 mass%, Al powder: 30 mass%, and weighed in a ball mill mixer for 5 hours. IPA (isopropyl alcohol) was used as the solvent. After drying the obtained mixed powder, an appropriate amount was filled in an alumina boat, and heat treatment was performed at 1000 ° C. for 2 hours in nitrogen gas having a purity of 99.9% or more. When the alumina boat was taken out after cooling to room temperature, the sample powder immediately after the heat treatment was agglomerated and thus crushed in a mortar. Table 3 shows the average particle diameter obtained by X-ray diffraction measurement for the obtained sample powder and conveniently obtained from the half width of the (110) peak of the bcc structure. In the X-ray diffraction pattern, a peak corresponding to alumina (α-Al 2 O 3 ) was obtained in addition to the peak of bcc structure (corresponding to FeCo alloy). In order to remove excess alumina particles, the magnetic separation operation described below was performed 20 times. That is, this is a magnetic separation operation in which a predetermined amount of sample powder is put into IPA, ultrasonic waves are applied for 10 minutes, and then only the magnetic particles are adsorbed by a permanent magnet to remove the supernatant. Table 3 shows the results of measuring the magnetic properties of the sample powder after magnetic separation by VSM. VSM used: In a vibrating sample magnetometer (VSM-5 type manufactured by Toei Kogyo Co., Ltd.), the applied magnetic field was measured at ± 2T. The volume fraction of Fe decreases due to the inclusion of alumina in the coating layer, and the saturation magnetization is about 80% of the Fe theoretical value. Further, in order to evaluate the corrosion resistance of this sample, 25 mg of the sample powder after magnetic separation was immersed in 1 ml of ammonia water having a pH of 11 for 96 hours, and the Fe and Co ion concentrations eluted in the solution were measured. The results are shown in Table 3. The amount of Fe and Co eluted was 0.5 ppm or less, and particles with a small amount of eluted and good corrosion resistance were obtained.
（比較例３）
鉄カルボニルと有機物混合体を加熱分解処理することにより、グラファイトで被覆された鉄微粒子を作製した。鉄−ペンタカルボニル６ｍｍｏｌ(１.１７５ｇ)とジ−n−プロピルアミン３ｍｍｏｌ(０.３０３ｇ)を混合し、減圧雰囲気下で加熱分解処理を行った。単位ｍｍｏｌはミリモル（×１０−３ｍｏｌ）である。９００℃×４５分の加熱反応を行い、同温度で３０分排気後、冷却した。得られたグラファイト被覆鉄粒子の磁気特性、酸素量、耐食性を実施例５と同様の方法で測定した。得られた結果を同じく表３に示す。
(Comparative Example 3)
Iron fine particles coated with graphite were prepared by heat decomposition treatment of iron carbonyl and organic substance mixture. 6 mmol (1.175 g) of iron-pentacarbonyl and 3 mmol (0.303 g) of di-n-propylamine were mixed and subjected to heat decomposition treatment under a reduced pressure atmosphere. The unit mmol is mmol (× 10 −3 mol). A heating reaction was performed at 900 ° C. for 45 minutes, and after evacuating for 30 minutes at the same temperature, cooling was performed. The magnetic properties, oxygen content, and corrosion resistance of the obtained graphite-coated iron particles were measured in the same manner as in Example 5. The obtained results are also shown in Table 3.
（実施例６）
平均粒径０．０３μｍのα−Ｆｅ２Ｏ３粉と平均粒径０．６μｍのＣｏ３Ｏ４粉とを所定の配合比（表４参照）となるよう秤量し、さらに平均粒径３μｍのＺｒＣ粉が２０ｍａｓｓ％となるように加えてボールミル混合機にて１６時間乾式混合した。得られた混合粉をアルミナボートに適量充填し、純度９９．９％以上の窒素ガス中にて１０００℃×２時間の熱処理を行なった。室温まで冷却した後にアルミナボートを取り出し、熱処理された試料粉末を回収した。
(Example 6)
An α-Fe 2 O 3 powder having an average particle size of 0.03 μm and a Co 3 O 4 powder having an average particle size of 0.6 μm are weighed so as to have a predetermined mixing ratio (see Table 4). ZrC powder was added so as to be 20 mass%, followed by dry mixing for 16 hours in a ball mill mixer. An appropriate amount of the obtained mixed powder was filled in an alumina boat and heat-treated at 1000 ° C. for 2 hours in nitrogen gas having a purity of 99.9% or more. After cooling to room temperature, the alumina boat was taken out and the heat-treated sample powder was collected.
上記試料粉末について２θ＝３０°〜８０°の範囲でＸ線回折測定を行い、面心立方晶構造（ｆｃｃ）の（１１１）ピークと体心立方晶構造（ｂｃｃ）の（１１０）ピークを検出した。ＭＤＩ社製解析ソフト「Ｊａｄｅ，ｖｅｒ．５」を用いて解析を行った。各回折ピーク強度の比（Ｉ（１１１）／Ｉ（１１０））、及び（１１０）ピークの半値幅より便宜的に求めたナノサイズ粒子の平均粒径を表５にまとめた。また上記Ｘ線回折パターンには、ＺｒＯ２、ＺｒＮの回折ピークも見られ、被覆物質の生成を確認した。また上記試料粉末の磁気特性を振動試料磁束計（ＶＳＭ）にて測定した結果も表５に示す。 The sample powder is subjected to X-ray diffraction measurement in the range of 2θ = 30 ° to 80 ° to detect the (111) peak of the face-centered cubic structure (fcc) and the (110) peak of the body-centered cubic structure (bcc). did. Analysis was performed using analysis software “Jade, ver. 5” manufactured by MDI. Table 5 summarizes the average particle diameters of the nano-sized particles that are conveniently obtained from the ratio of the diffraction peak intensities (I (111) / I (110)) and the half-value width of the (110) peak. In the X-ray diffraction pattern, diffraction peaks of ZrO 2 and ZrN were also observed, confirming the formation of a coating material. Table 5 also shows the results of measuring the magnetic properties of the sample powder with a vibrating sample magnetometer (VSM).
（実施例７〜１０）
平均粒径０．０３μｍのα−Ｆｅ２Ｏ３粉と平均粒径０．４μｍのＮｉＯ粉とを所定の配合比（表６参照）となるよう秤量し、さらに平均粒径０．０２μｍのカーボンブラック粉が３０ｍａｓｓ％となるように加えてＶ字型ミキサーにて２４時間混合した。得られた混合粉をアルミナボートに適量充填し、純度９９．９％以上の窒素ガスを用いて雰囲気酸素量を１０ｐｐｍ以下に制御し、１０００℃×２時間の熱処理を行なった。加熱処理終了後に室温まで冷却した後にアルミナボートを取り出し、熱処理された試料粉末を回収した。上記試料粉末について実施例１〜４と同様に評価を行い、Ｘ線回折測定及び磁気測定を行った。面心立方晶構造（ｆｃｃ）の（１１１）ピークの半値幅より便宜的に求めた平均粒径、および磁気特性を表７に示す。
(Examples 7 to 10)
Α-Fe 2 O 3 powder having an average particle size of 0.03 μm and NiO powder having an average particle size of 0.4 μm are weighed so as to have a predetermined mixing ratio (see Table 6), and carbon having an average particle size of 0.02 μm. It added so that black powder might be 30 mass%, and it mixed for 24 hours with the V-shaped mixer. An appropriate amount of the obtained mixed powder was filled into an alumina boat, and the amount of atmospheric oxygen was controlled to 10 ppm or less using nitrogen gas having a purity of 99.9% or more, and heat treatment was performed at 1000 ° C. for 2 hours. After the heat treatment, the alumina boat was taken out after cooling to room temperature, and the heat-treated sample powder was collected. The sample powder was evaluated in the same manner as in Examples 1 to 4, and X-ray diffraction measurement and magnetic measurement were performed. Table 7 shows the average particle diameter and magnetic properties obtained for convenience from the half width of the (111) peak of the face-centered cubic structure (fcc).
（比較例４、５）
表６に示す混合比で原料を混合した以外は実施例７〜１０と同様に試料を作成し、評価した。得られた平均粒径および磁気特性を表７に示す。
(Comparative Examples 4 and 5)
Samples were prepared and evaluated in the same manner as in Examples 7 to 10 except that the raw materials were mixed at the mixing ratio shown in Table 6. Table 7 shows the obtained average particle diameter and magnetic properties.
表７によれば、実施例７〜１０の保磁力は比較例１（Ｆｅ単体粒子）、５（Ｎｉ単体粒子）に比べて小さいことが分かる。すなわちＦｅにＮｉを含めることにより低保磁力化することを示している。また比較例４では保磁力が低くなっているが、飽和磁化も極めて小さくなっている。比較例４の組成はインバー合金に相当するため、磁化が急激に低下している。以上より、Ｎｉ/Ｆｅが０．０１〜０．１および０．４〜１５の範囲で２.０ｋＡ／ｍ以下の低保磁力と４０Ａｍ２／ｋｇ以上の飽和磁化を有する金属磁性粒子が得られた。また実施例９の試料から得られた代表的な電子顕微鏡写真を図４に、またその模式図を図５に示す。粒径約７０ｎｍのＦｅＮｉ合金粒子１２が５〜１５ｎｍのＣ膜１３により被覆されている。実施例７、８、１０についても同様の被覆粒子が観察された。 According to Table 7, it can be seen that the coercive forces of Examples 7 to 10 are smaller than those of Comparative Example 1 (Fe simple particles) and 5 (Ni simple particles). That is, it is shown that the coercive force is reduced by including Ni in Fe. In Comparative Example 4, the coercive force is low, but the saturation magnetization is also extremely small. Since the composition of Comparative Example 4 corresponds to an Invar alloy, the magnetization rapidly decreases. From the above, metal magnetic particles having a low coercive force of 2.0 kA / m or less and a saturation magnetization of 40 Am 2 / kg or more in a range of Ni / Fe of 0.01 to 0.1 and 0.4 to 15 are obtained. It was. Moreover, the typical electron micrograph obtained from the sample of Example 9 is shown in FIG. 4, and the schematic diagram is shown in FIG. FeNi alloy particles 12 having a particle size of about 70 nm are covered with a C film 13 having a thickness of 5 to 15 nm. Similar coated particles were observed in Examples 7, 8, and 10.
（実施例１１）
平均粒径０．０３μｍのα−Ｆｅ２Ｏ３粉を６４ｍａｓｓ％、平均粒径０．６μｍのＣｏ３Ｏ４粉を３６ｍａｓｓ％となるように秤量し、Ｖ字型ミキサーにて８時間乾式混合した。得られた混合粉を「前処理粉」とし、前処理粉を７０ｍａｓｓ％、平均粒径１μｍのほう素粉末を１２．５ｍａｓｓ％、平均粒径５μｍの炭素粉末を１２．５ｍａｓｓ％となるように秤量してボールミル混合機にて１６時間湿式混合した。なお、溶媒として純水を用い、粉末重量に対して4倍重量加えた。得られた混合粉をアルミナボートに適量充填し、純度９９．９％以上の窒素ガス中にて１３００℃×２時間の熱処理を行なった。室温まで冷却した後にアルミナボートを取り出し、熱処理された試料粉末を回収した。試料粉末について実施例１と同様にして測定したＸ線回折ピーク強度比（Ｉ（１１１）/Ｉ（１１０））、平均粒径、磁気特性を表８に示す。また本実施例の試料から得られた代表的な電子顕微鏡写真を図６に、またその模式図を図７に示す。約３００ｎｍのＦｅＣｏ粒子１４が約１００ｎｍのＢＮ被覆層１５で被覆されている。粒子１０８個についてＢＮ被覆層の厚みを計測することによって得られた平均被覆膜厚は１１６ｎｍであった。なお、コア粒子および被覆層の組成同定は電子顕微鏡付属のエネルギー分散型Ｘ線分光装置および電子エネルギー損失分光装置により実施した。更に耐蝕性を評価するため、実施例５と同様にＦｅおよびＣｏイオン溶出量を測定した。結果を表８に示す。ＦｅおよびCoの溶出量は、０．５ｐｐｍ以下となり、溶出量の少ない耐食性の良好な粒子が得られた。
(Example 11)
Weigh α-Fe 2 O 3 powder with an average particle size of 0.03 μm to 64 mass% and Co 3 O 4 powder with an average particle size of 0.6 μm to 36 mass%, and dry-mix for 8 hours with a V-shaped mixer. did. The obtained mixed powder is “pretreated powder”, the pretreated powder is 70 mass%, boron powder having an average particle diameter of 1 μm is 12.5 mass%, and carbon powder having an average particle diameter of 5 μm is 12.5 mass%. Weighed and wet mixed in a ball mill mixer for 16 hours. In addition, pure water was used as a solvent, and 4 times the weight of the powder was added. An appropriate amount of the obtained mixed powder was filled in an alumina boat and heat-treated at 1300 ° C. for 2 hours in nitrogen gas having a purity of 99.9% or more. After cooling to room temperature, the alumina boat was taken out and the heat-treated sample powder was collected. Table 8 shows the X-ray diffraction peak intensity ratio (I (111) / I (110)), average particle diameter, and magnetic properties measured for the sample powder in the same manner as in Example 1. A typical electron micrograph obtained from the sample of this example is shown in FIG. 6, and a schematic diagram thereof is shown in FIG. About 300 nm FeCo particles 14 are covered with a BN coating layer 15 of about 100 nm. The average coating thickness obtained by measuring the thickness of the BN coating layer for 108 particles was 116 nm. The composition identification of the core particles and the coating layer was performed using an energy dispersive X-ray spectrometer and an electron energy loss spectrometer attached to an electron microscope. Further, in order to evaluate the corrosion resistance, the elution amounts of Fe and Co ions were measured in the same manner as in Example 5. The results are shown in Table 8. The amount of Fe and Co eluted was 0.5 ppm or less, and particles with a small amount of eluted and good corrosion resistance were obtained.
本発明は、磁気テープ、磁気記録ディスクなどの磁気記録媒体や、電波吸収体、インダクタ、プリント基板等の電子デバイス（ヨークなどの軟磁性形状体）や、生体物質抽出用の磁気ビーズなどに利用される磁性金属粒子およびその製造方法として利用することができる。 The present invention is used for magnetic recording media such as magnetic tapes and magnetic recording disks, electronic devices such as radio wave absorbers, inductors and printed boards (soft magnetic bodies such as yokes), magnetic beads for extracting biological materials, and the like. It can be used as a magnetic metal particle and a method for producing the same.
１ ＦｅＣｏ粒子、 ２ 円環模様、 ３ Ｃ膜、 ５ ＦｅＣｏ粒子、
６ Ｃ膜、 １０ 他の被覆粒子、 １１ 他の被覆粒子、１２ ＦｅＮｉ粒子
１３ Ｃ膜、 １４ ＦｅＣｏ粒子、 １５ ＢＮ被覆
1 FeCo particle, 2 annular pattern, 3 C film, 5 FeCo particle,
6 C film, 10 other coated particles, 11 other coated particles, 12 FeNi particles 13 C film, 14 FeCo particles, 15 BN coated
Claims (4)
ＮｉとＦｅの質量比Ｎｉ／Ｆｅが０．０１〜０．１または０．４〜１５のいずれかの範囲であるとともに、
膜厚が１〜２００ｎｍのＣの被覆層を有することを特徴とする鉄系ナノサイズ粒子。 Spherical metal particles having a composition containing Fe as a main component and containing Ni,
While the mass ratio Ni / Fe of Ni and Fe is in the range of 0.01 to 0.1 or 0.4 to 15,
An iron-based nanosized particle having a C coating layer having a thickness of 1 to 200 nm.
ＮｉとＦｅの質量比Ｎｉ／Ｆｅが０．０１〜０．１または０．４〜１５のいずれかの範囲であるとともに、
膜厚が１〜２００ｎｍの被覆層を有し、
前記被覆層は、金属元素Ｍ（金属元素Ｍは、Ａｌ、Ａｓ、Ｂ、Ｃｅ、Ｃｏ、Ｃｒ、Ｇａ、Ｈｆ、Ｉｎ、Ｍｎ、Ｎｂ、Ｔｉ、Ｖ、Ｚｒ、Ｓｃ、Ｓｉ、Ｙ、Ｔａから選ばれた一種以上）の酸化物もしくは窒化物であることを特徴とする鉄系ナノサイズ粒子。 Spherical metal particles having a composition containing Fe as a main component and containing Ni,
While the mass ratio Ni / Fe of Ni and Fe is in the range of 0.01 to 0.1 or 0.4 to 15,
Having a coating layer with a thickness of 1 to 200 nm,
The coating layer is made of a metal element M (the metal element M is made of Al, As, B, Ce, Co, Cr, Ga, Hf, In, Mn, Nb, Ti, V, Zr, Sc, Si, Y, Ta. Iron-based nanosize particles characterized by being one or more selected oxides or nitrides.
Ｆｅを主成分とし、Ｎｉを含む組成を有する球状の金属粒子であり、ＮｉとＦｅの質量比Ｎｉ／Ｆｅが０．０１〜０．１または０．４〜１５のいずれかの範囲であるとともに、膜厚が１〜２００ｎｍのＣの被覆層を有する鉄系ナノサイズ粒子を得ることを特徴とする鉄系ナノサイズ粒子の製造方法。 By mixing an oxide powder containing Ni with Fe as a main component and a powder containing C into a mixed powder, and heat-treating the mixed powder in a non-oxidizing atmosphere,
Spherical metal particles having a composition containing Ni as a main component and containing Ni, and the mass ratio Ni / Fe of Ni and Fe is in the range of 0.01 to 0.1 or 0.4 to 15 A method for producing iron-based nano-sized particles, comprising obtaining iron-based nano-sized particles having a C coating layer having a thickness of 1 to 200 nm.
Ｆｅを主成分とし、Ｎｉを含む組成を有する球状の金属粒子であり、ＮｉとＦｅの質量比Ｎｉ／Ｆｅが０．０１〜０．１または０．４〜１５のいずれかの範囲であるとともに、膜厚が１〜２００ｎｍの金属元素Ｍの酸化物もしくは窒化物の被覆層を有する鉄系ナノサイズ粒子を得ることを特徴とする鉄系ナノサイズ粒子の製造方法。 Oxide powder containing Ni as a main component of Fe, and metal element M (metal element M is Al, As, B, Ce, Co, Cr, Ga, Hf, In, Mn, Nb, Ti, V, Zr, By mixing with a powder containing one or more selected from Sc, Si, Y, Ta), and heat-treating the mixed powder in a non-oxidizing atmosphere,
Spherical metal particles having a composition containing Ni as a main component and containing Ni, and the mass ratio Ni / Fe of Ni and Fe is in the range of 0.01 to 0.1 or 0.4 to 15 A method for producing iron-based nano-sized particles, comprising obtaining iron-based nano-sized particles having a coating layer of an oxide or nitride of a metal element M having a thickness of 1 to 200 nm.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2011153409A JP5556756B2 (en) | 2004-02-27 | 2011-07-12 | Iron-based nano-sized particles and method for producing the same |
Applications Claiming Priority (3)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2004053554 | 2004-02-27 | ||
| JP2004053554 | 2004-02-27 | ||
| JP2011153409A JP5556756B2 (en) | 2004-02-27 | 2011-07-12 | Iron-based nano-sized particles and method for producing the same |
Related Parent Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP2005045156A Division JP4895151B2 (en) | 2004-02-27 | 2005-02-22 | Iron-based nano-sized particles and method for producing the same |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JP2011246820A true JP2011246820A (en) | 2011-12-08 |
| JP5556756B2 JP5556756B2 (en) | 2014-07-23 |
Family
ID=45412434
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP2011153409A Expired - Fee Related JP5556756B2 (en) | 2004-02-27 | 2011-07-12 | Iron-based nano-sized particles and method for producing the same |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP5556756B2 (en) |
Cited By (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2013089929A (en) * | 2011-10-24 | 2013-05-13 | Tdk Corp | Soft magnetic powder, powder magnetic core, and magnetic device |
| JP2013149854A (en) * | 2012-01-20 | 2013-08-01 | Dowa Electronics Materials Co Ltd | Magnetic component, soft magnetic metal powder used therefor, and method of manufacturing the same |
| WO2014141318A1 (en) * | 2013-03-13 | 2014-09-18 | Ｄｏｗａエレクトロニクス株式会社 | Magnetic component, soft magnetic metal powder used in same, and method for producing same |
| KR20180081787A (en) * | 2015-11-19 | 2018-07-17 | 매튜 메이 | Compositions of nanoparticles having circular gradients and methods of using the same |
| US20210050132A1 (en) * | 2018-01-17 | 2021-02-18 | Dowa Electronics Materials Co., Ltd. | Silicon oxide-coated iron powder, method for producing the same, molded body for inductor using the same, and inductor |
| CN114561595A (en) * | 2022-02-21 | 2022-05-31 | 上海交通大学 | Nano precipitated phase and oxide composite dispersion strengthened alloy and preparation and application thereof |
Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH0459903A (en) * | 1990-06-28 | 1992-02-26 | Tdk Corp | Manufacture of ferromagnetic super fine particles, ferromagnetic super fine particles for fixing physiologically active material and physiologically active material fixing ferromagnetic super fine particles |
| JPH04160102A (en) * | 1990-10-22 | 1992-06-03 | Matsushita Electric Ind Co Ltd | Composite material and its production |
| JPH09143502A (en) * | 1995-11-27 | 1997-06-03 | Agency Of Ind Science & Technol | Graphite coated metallic particle and its production |
| JP2002507055A (en) * | 1998-03-09 | 2002-03-05 | ユニベルシテイト ユトレヒト | Ferromagnetic particles |
| JP2002356708A (en) * | 2001-05-30 | 2002-12-13 | Tdk Corp | Method for manufacturing magnetic metal powder, and magnetic metal powder |
-
2011
- 2011-07-12 JP JP2011153409A patent/JP5556756B2/en not_active Expired - Fee Related
Patent Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH0459903A (en) * | 1990-06-28 | 1992-02-26 | Tdk Corp | Manufacture of ferromagnetic super fine particles, ferromagnetic super fine particles for fixing physiologically active material and physiologically active material fixing ferromagnetic super fine particles |
| JPH04160102A (en) * | 1990-10-22 | 1992-06-03 | Matsushita Electric Ind Co Ltd | Composite material and its production |
| JPH09143502A (en) * | 1995-11-27 | 1997-06-03 | Agency Of Ind Science & Technol | Graphite coated metallic particle and its production |
| JP2002507055A (en) * | 1998-03-09 | 2002-03-05 | ユニベルシテイト ユトレヒト | Ferromagnetic particles |
| JP2002356708A (en) * | 2001-05-30 | 2002-12-13 | Tdk Corp | Method for manufacturing magnetic metal powder, and magnetic metal powder |
Cited By (10)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2013089929A (en) * | 2011-10-24 | 2013-05-13 | Tdk Corp | Soft magnetic powder, powder magnetic core, and magnetic device |
| JP2013149854A (en) * | 2012-01-20 | 2013-08-01 | Dowa Electronics Materials Co Ltd | Magnetic component, soft magnetic metal powder used therefor, and method of manufacturing the same |
| WO2014141318A1 (en) * | 2013-03-13 | 2014-09-18 | Ｄｏｗａエレクトロニクス株式会社 | Magnetic component, soft magnetic metal powder used in same, and method for producing same |
| KR101496626B1 (en) | 2013-03-13 | 2015-02-26 | 도와 일렉트로닉스 가부시키가이샤 | Magnetic component, and soft magnetic metal powder used therein and manufacturing method thereof |
| KR20180081787A (en) * | 2015-11-19 | 2018-07-17 | 매튜 메이 | Compositions of nanoparticles having circular gradients and methods of using the same |
| JP2018536098A (en) * | 2015-11-19 | 2018-12-06 | メイエ，マシュー | Radial gradient nanoparticle compounds and methods of use |
| KR102159870B1 (en) * | 2015-11-19 | 2020-09-24 | 매튜 메이 | Compositions of nanoparticles with radial concentration gradient and method of using the |
| JP7102345B2 (en) | 2015-11-19 | 2022-07-19 | メイエ，マシュー | Radial Gradation Nanoparticle Compounds and Their Usage |
| US20210050132A1 (en) * | 2018-01-17 | 2021-02-18 | Dowa Electronics Materials Co., Ltd. | Silicon oxide-coated iron powder, method for producing the same, molded body for inductor using the same, and inductor |
| CN114561595A (en) * | 2022-02-21 | 2022-05-31 | 上海交通大学 | Nano precipitated phase and oxide composite dispersion strengthened alloy and preparation and application thereof |
Also Published As
| Publication number | Publication date |
|---|---|
| JP5556756B2 (en) | 2014-07-23 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| JP4895151B2 (en) | Iron-based nano-sized particles and method for producing the same | |
| JP5556756B2 (en) | Iron-based nano-sized particles and method for producing the same | |
| JP5359905B2 (en) | Fine metal particles, method for producing the same, and magnetic beads | |
| WO2012099202A1 (en) | Ferromagnetic granular powder and method for manufacturing same, as well as anisotropic magnet, bonded magnet, and pressed-powder magnet | |
| JP2006097123A (en) | Metallic microparticle, manufacturing method therefor, and magnetic bead | |
| JP3848486B2 (en) | Iron nitride magnetic powder material for magnetic recording medium, method for producing the same, and magnetic recording medium | |
| JP2000277311A5 (en) | ||
| Okada et al. | Direct preparation of submicron-sized Sm2Fe17 ultra-fine powders by reduction-diffusion technique | |
| EP3690071A1 (en) | Magnetic material and method for producing same | |
| JP5168637B2 (en) | Metal magnetic fine particles and production method thereof, dust core | |
| JP2008081818A (en) | Method for producing precursor powder of nickel-ferroalloy nanoparticle, precursor powder of nickel-ferroalloy nanoparticle, method for producing nickel-ferroalloy nanoparticle, and nickel-ferroalloy nanoparticle | |
| WO2006100986A1 (en) | Coated metal fine particle and method for producing same | |
| JP2007046074A (en) | Fine metal particle and manufacturing method therefor | |
| JP2007046074A5 (en) | ||
| JP4288674B2 (en) | Method for producing magnetic metal fine particles and magnetic metal fine particles | |
| JP4320729B2 (en) | Method for producing magnetic metal particles | |
| JP2004319923A (en) | Iron nitride-based magnetic powder | |
| JP2004281846A (en) | High-frequency magnetic material, high-frequency magnetic part using the same, and method for manufacturing the same | |
| Wu et al. | Magnetic properties and thermal stability of γ′-Fe4N nanoparticles prepared by a combined method of reduction and nitriding | |
| Ram et al. | Granular GMR sensors of Co–Cu and Co–Ag nanoparticles synthesized through a chemical route using NaBH4 | |
| Marinca et al. | Structural, thermal and magnetic characteristics of Fe3O4/Ni3Fe composite powder obtained by mechanosynthesis-annealing route | |
| JP2008069431A (en) | Method for producing magnetic particle, and magnetic particle | |
| JP4444191B2 (en) | High frequency magnetic material, high frequency magnetic device, and method of manufacturing high frequency magnetic material | |
| JP4304668B2 (en) | Metal fine particles and method for producing metal fine particles | |
| JP4502978B2 (en) | Iron nitride magnetic powder material, method for producing the same, and magnetic recording medium |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| A521 | Request for written amendment filed |
Free format text: JAPANESE INTERMEDIATE CODE: A523 Effective date: 20120920 |
|
| A131 | Notification of reasons for refusal |
Free format text: JAPANESE INTERMEDIATE CODE: A131 Effective date: 20130524 |
|
| A521 | Request for written amendment filed |
Free format text: JAPANESE INTERMEDIATE CODE: A523 Effective date: 20130705 |
|
| A131 | Notification of reasons for refusal |
Free format text: JAPANESE INTERMEDIATE CODE: A131 Effective date: 20130920 |
|
| TRDD | Decision of grant or rejection written | ||
| A01 | Written decision to grant a patent or to grant a registration (utility model) |
Free format text: JAPANESE INTERMEDIATE CODE: A01 Effective date: 20140507 |
|
| A61 | First payment of annual fees (during grant procedure) |
Free format text: JAPANESE INTERMEDIATE CODE: A61 Effective date: 20140520 |
|
| R150 | Certificate of patent or registration of utility model |
Ref document number: 5556756 Country of ref document: JP Free format text: JAPANESE INTERMEDIATE CODE: R150 |
|
| LAPS | Cancellation because of no payment of annual fees |