JP2005330526A - Method for producing nanoparticle group - Google Patents
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- 239000002105 nanoparticle Substances 0.000 title claims abstract description 57
- 238000004519 manufacturing process Methods 0.000 title claims abstract description 19
- XEEYBQQBJWHFJM-UHFFFAOYSA-N iron Substances [Fe] XEEYBQQBJWHFJM-UHFFFAOYSA-N 0.000 claims abstract description 94
- 239000002245 particle Substances 0.000 claims abstract description 84
- 229910052742 iron Inorganic materials 0.000 claims abstract description 39
- 229910052697 platinum Inorganic materials 0.000 claims abstract description 39
- 239000000203 mixture Substances 0.000 claims abstract description 34
- 229910052763 palladium Inorganic materials 0.000 claims abstract description 33
- 239000003223 protective agent Substances 0.000 claims abstract description 20
- 238000010438 heat treatment Methods 0.000 claims abstract description 18
- 238000000034 method Methods 0.000 claims abstract description 17
- 239000012298 atmosphere Substances 0.000 claims abstract description 11
- 239000003960 organic solvent Substances 0.000 claims abstract description 7
- BASFCYQUMIYNBI-UHFFFAOYSA-N platinum Substances [Pt] BASFCYQUMIYNBI-UHFFFAOYSA-N 0.000 claims description 56
- KDLHZDBZIXYQEI-UHFFFAOYSA-N palladium Substances [Pd] KDLHZDBZIXYQEI-UHFFFAOYSA-N 0.000 claims description 47
- 229910005335 FePt Inorganic materials 0.000 claims description 28
- 229910015187 FePd Inorganic materials 0.000 claims description 9
- 229910045601 alloy Inorganic materials 0.000 claims description 8
- 239000000956 alloy Substances 0.000 claims description 8
- XYFCBTPGUUZFHI-UHFFFAOYSA-N Phosphine Chemical compound P XYFCBTPGUUZFHI-UHFFFAOYSA-N 0.000 claims description 6
- 150000002894 organic compounds Chemical class 0.000 claims description 6
- 229910002056 binary alloy Inorganic materials 0.000 claims description 5
- 125000004432 carbon atom Chemical group C* 0.000 claims description 4
- JKDRQYIYVJVOPF-FDGPNNRMSA-L palladium(ii) acetylacetonate Chemical compound [Pd+2].C\C([O-])=C\C(C)=O.C\C([O-])=C\C(C)=O JKDRQYIYVJVOPF-FDGPNNRMSA-L 0.000 claims description 4
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- PIICEJLVQHRZGT-UHFFFAOYSA-N Ethylenediamine Chemical compound NCCN PIICEJLVQHRZGT-UHFFFAOYSA-N 0.000 claims description 3
- ABLZXFCXXLZCGV-UHFFFAOYSA-N Phosphorous acid Chemical compound OP(O)=O ABLZXFCXXLZCGV-UHFFFAOYSA-N 0.000 claims description 3
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- 150000004945 aromatic hydrocarbons Chemical group 0.000 claims description 3
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- 150000002430 hydrocarbons Chemical group 0.000 claims description 3
- 150000002941 palladium compounds Chemical class 0.000 claims description 3
- UQPUONNXJVWHRM-UHFFFAOYSA-N palladium;triphenylphosphane Chemical compound [Pd].C1=CC=CC=C1P(C=1C=CC=CC=1)C1=CC=CC=C1 UQPUONNXJVWHRM-UHFFFAOYSA-N 0.000 claims description 3
- ACVYVLVWPXVTIT-UHFFFAOYSA-N phosphinic acid Chemical compound O[PH2]=O ACVYVLVWPXVTIT-UHFFFAOYSA-N 0.000 claims description 3
- 229910000073 phosphorus hydride Inorganic materials 0.000 claims description 3
- 150000003058 platinum compounds Chemical class 0.000 claims description 3
- UIRRQIANMRREBL-UHFFFAOYSA-N platinum;triethylphosphane Chemical compound [Pt].CCP(CC)CC UIRRQIANMRREBL-UHFFFAOYSA-N 0.000 claims description 3
- XAKYZBMFCZISAU-UHFFFAOYSA-N platinum;triphenylphosphane Chemical compound [Pt].C1=CC=CC=C1P(C=1C=CC=CC=1)C1=CC=CC=C1 XAKYZBMFCZISAU-UHFFFAOYSA-N 0.000 claims description 3
- 230000009467 reduction Effects 0.000 claims description 3
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- 238000009826 distribution Methods 0.000 abstract description 16
- 229910001252 Pd alloy Inorganic materials 0.000 abstract 2
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- LFQSCWFLJHTTHZ-UHFFFAOYSA-N Ethanol Chemical compound CCO LFQSCWFLJHTTHZ-UHFFFAOYSA-N 0.000 description 23
- QGLWBTPVKHMVHM-KTKRTIGZSA-N (z)-octadec-9-en-1-amine Chemical compound CCCCCCCC\C=C/CCCCCCCCN QGLWBTPVKHMVHM-KTKRTIGZSA-N 0.000 description 22
- WRIDQFICGBMAFQ-UHFFFAOYSA-N (E)-8-Octadecenoic acid Natural products CCCCCCCCCC=CCCCCCCC(O)=O WRIDQFICGBMAFQ-UHFFFAOYSA-N 0.000 description 21
- LQJBNNIYVWPHFW-UHFFFAOYSA-N 20:1omega9c fatty acid Natural products CCCCCCCCCCC=CCCCCCCCC(O)=O LQJBNNIYVWPHFW-UHFFFAOYSA-N 0.000 description 21
- QSBYPNXLFMSGKH-UHFFFAOYSA-N 9-Heptadecensaeure Natural products CCCCCCCC=CCCCCCCCC(O)=O QSBYPNXLFMSGKH-UHFFFAOYSA-N 0.000 description 21
- ZQPPMHVWECSIRJ-UHFFFAOYSA-N Oleic acid Natural products CCCCCCCCC=CCCCCCCCC(O)=O ZQPPMHVWECSIRJ-UHFFFAOYSA-N 0.000 description 21
- 239000005642 Oleic acid Substances 0.000 description 21
- QXJSBBXBKPUZAA-UHFFFAOYSA-N isooleic acid Natural products CCCCCCCC=CCCCCCCCCC(O)=O QXJSBBXBKPUZAA-UHFFFAOYSA-N 0.000 description 21
- ZQPPMHVWECSIRJ-KTKRTIGZSA-N oleic acid Chemical compound CCCCCCCC\C=C/CCCCCCCC(O)=O ZQPPMHVWECSIRJ-KTKRTIGZSA-N 0.000 description 21
- 239000006185 dispersion Substances 0.000 description 15
- KLFRPGNCEJNEKU-FDGPNNRMSA-L (z)-4-oxopent-2-en-2-olate;platinum(2+) Chemical compound [Pt+2].C\C([O-])=C\C(C)=O.C\C([O-])=C\C(C)=O KLFRPGNCEJNEKU-FDGPNNRMSA-L 0.000 description 14
- 238000009835 boiling Methods 0.000 description 14
- 239000002244 precipitate Substances 0.000 description 14
- NKJOXAZJBOMXID-UHFFFAOYSA-N 1,1'-Oxybisoctane Chemical compound CCCCCCCCOCCCCCCCC NKJOXAZJBOMXID-UHFFFAOYSA-N 0.000 description 13
- 238000001816 cooling Methods 0.000 description 13
- 239000000126 substance Substances 0.000 description 13
- 238000003756 stirring Methods 0.000 description 11
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- 239000013078 crystal Substances 0.000 description 7
- 239000000696 magnetic material Substances 0.000 description 7
- 238000001556 precipitation Methods 0.000 description 6
- 230000015572 biosynthetic process Effects 0.000 description 5
- 229910018979 CoPt Inorganic materials 0.000 description 4
- 239000006249 magnetic particle Substances 0.000 description 4
- 238000003786 synthesis reaction Methods 0.000 description 4
- BTOOAFQCTJZDRC-UHFFFAOYSA-N 1,2-hexadecanediol Chemical compound CCCCCCCCCCCCCCC(O)CO BTOOAFQCTJZDRC-UHFFFAOYSA-N 0.000 description 3
- 239000003638 chemical reducing agent Substances 0.000 description 3
- 238000000354 decomposition reaction Methods 0.000 description 3
- USIUVYZYUHIAEV-UHFFFAOYSA-N diphenyl ether Chemical compound C=1C=CC=CC=1OC1=CC=CC=C1 USIUVYZYUHIAEV-UHFFFAOYSA-N 0.000 description 3
- 229910052751 metal Inorganic materials 0.000 description 3
- 239000002184 metal Substances 0.000 description 3
- 239000012454 non-polar solvent Substances 0.000 description 3
- 239000002994 raw material Substances 0.000 description 3
- 239000000758 substrate Substances 0.000 description 3
- IJGRMHOSHXDMSA-UHFFFAOYSA-N Atomic nitrogen Chemical compound N#N IJGRMHOSHXDMSA-UHFFFAOYSA-N 0.000 description 2
- 239000006087 Silane Coupling Agent Substances 0.000 description 2
- 238000003917 TEM image Methods 0.000 description 2
- 230000002776 aggregation Effects 0.000 description 2
- 238000004220 aggregation Methods 0.000 description 2
- 125000004429 atom Chemical group 0.000 description 2
- 230000005540 biological transmission Effects 0.000 description 2
- 125000002915 carbonyl group Chemical group [*:2]C([*:1])=O 0.000 description 2
- 150000001735 carboxylic acids Chemical class 0.000 description 2
- 239000011258 core-shell material Substances 0.000 description 2
- 238000001035 drying Methods 0.000 description 2
- 230000001747 exhibiting effect Effects 0.000 description 2
- 238000002474 experimental method Methods 0.000 description 2
- 150000002500 ions Chemical class 0.000 description 2
- 229940087654 iron carbonyl Drugs 0.000 description 2
- 239000007791 liquid phase Substances 0.000 description 2
- 239000002923 metal particle Substances 0.000 description 2
- PHQOGHDTIVQXHL-UHFFFAOYSA-N n'-(3-trimethoxysilylpropyl)ethane-1,2-diamine Chemical compound CO[Si](OC)(OC)CCCNCCN PHQOGHDTIVQXHL-UHFFFAOYSA-N 0.000 description 2
- -1 platinum ions Chemical class 0.000 description 2
- 238000004544 sputter deposition Methods 0.000 description 2
- 230000007704 transition Effects 0.000 description 2
- CMCBDXRRFKYBDG-UHFFFAOYSA-N 1-dodecoxydodecane Chemical compound CCCCCCCCCCCCOCCCCCCCCCCCC CMCBDXRRFKYBDG-UHFFFAOYSA-N 0.000 description 1
- 229910019222 CoCrPt Inorganic materials 0.000 description 1
- 229910016583 MnAl Inorganic materials 0.000 description 1
- 229910016629 MnBi Inorganic materials 0.000 description 1
- 235000021355 Stearic acid Nutrition 0.000 description 1
- 238000002441 X-ray diffraction Methods 0.000 description 1
- 238000004458 analytical method Methods 0.000 description 1
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- 238000000975 co-precipitation Methods 0.000 description 1
- 230000007423 decrease Effects 0.000 description 1
- 230000002542 deteriorative effect Effects 0.000 description 1
- MHDVGSVTJDSBDK-UHFFFAOYSA-N dibenzyl ether Chemical compound C=1C=CC=CC=1COCC1=CC=CC=C1 MHDVGSVTJDSBDK-UHFFFAOYSA-N 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 238000005516 engineering process Methods 0.000 description 1
- 239000010419 fine particle Substances 0.000 description 1
- 238000002173 high-resolution transmission electron microscopy Methods 0.000 description 1
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- 229910000765 intermetallic Inorganic materials 0.000 description 1
- 150000002576 ketones Chemical class 0.000 description 1
- 239000007788 liquid Substances 0.000 description 1
- 239000000463 material Substances 0.000 description 1
- 230000007246 mechanism Effects 0.000 description 1
- 239000002082 metal nanoparticle Substances 0.000 description 1
- 239000000693 micelle Substances 0.000 description 1
- 239000012046 mixed solvent Substances 0.000 description 1
- 238000002156 mixing Methods 0.000 description 1
- 229910052757 nitrogen Inorganic materials 0.000 description 1
- QIQXTHQIDYTFRH-UHFFFAOYSA-N octadecanoic acid Chemical compound CCCCCCCCCCCCCCCCCC(O)=O QIQXTHQIDYTFRH-UHFFFAOYSA-N 0.000 description 1
- OQCDKBAXFALNLD-UHFFFAOYSA-N octadecanoic acid Natural products CCCCCCCC(C)CCCCCCCCC(O)=O OQCDKBAXFALNLD-UHFFFAOYSA-N 0.000 description 1
- 230000003647 oxidation Effects 0.000 description 1
- 238000007254 oxidation reaction Methods 0.000 description 1
- BOTNYLSAWDQNEX-UHFFFAOYSA-N phenoxymethylbenzene Chemical compound C=1C=CC=CC=1COC1=CC=CC=C1 BOTNYLSAWDQNEX-UHFFFAOYSA-N 0.000 description 1
- 239000002798 polar solvent Substances 0.000 description 1
- 229920005862 polyol Polymers 0.000 description 1
- 150000003077 polyols Chemical class 0.000 description 1
- 150000003839 salts Chemical class 0.000 description 1
- 229910000938 samarium–cobalt magnet Inorganic materials 0.000 description 1
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- 238000005245 sintering Methods 0.000 description 1
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Abstract
Description
本発明は超高密度記録媒体用の磁性粒子として用いることができるナノ粒子群の製造方法に関し、より詳細には、FeとPtまたはPdの2元合金よりなるナノ粒子群の製造方法に関する。 The present invention relates to a method for producing a group of nanoparticles that can be used as magnetic particles for an ultra-high density recording medium, and more particularly to a method for producing a group of nanoparticles comprising a binary alloy of Fe and Pt or Pd.
磁気記録媒体の記録密度を向上させるために、粒子サイズを微小化する検討がなされている。ハードディスク媒体では、用いられる磁性材料はCoCrPt等の合金であるが、結晶異方性エネルギー(Ku)が106erg/cm3程度であるため、熱揺らぎの観点から実用可能な粒子サイズは10nm程度と考えられている。粒子サイズを更に微小化するためには、より高いKuを有する磁性材料を用いることが必要である。このような磁性材料としてはCo3Pt、CoPt、CoPt3、Fe3Pt、FePt、FePt3、FePd、MnBi、MnAl、SmCo5、Sm2Co17などの金属間化合物、合金が挙げられる。特にFePt,FePd及びCoPt等の磁性材料は、CuAu型のL10規則相において大きな一軸結晶磁気異方性(FePt:7×107erg/cm3,CoPt:5×107 erg/cm3)を示すことから、高密度磁気記録における熱揺らぎの問題を解決する磁性材料として着目されている。
近年、これらの材料を用いたスパッタ法による成膜の検討が盛んであり、保磁力が10000 Oe(796kA/m)に達するメディアも報告されている。しかしながら、得られる粒子サイズ分布を狭めることが困難で、信号対雑音比(S/N比)が十分でないのが現状である。
粒子サイズ分布が非常に狭いナノサイズの磁性粒子を作るために、近年、液相中での合成が試みられている。液相合成法とは金属塩、有機金属などを液中に溶解させ、還元あるいは分解などにより、粒子を析出させる方法である。微粒子を合成する公知の方法として共沈法、ホットソープ法、逆ミセル法などがある。
In order to improve the recording density of a magnetic recording medium, studies have been made to reduce the particle size. In hard disk media, the magnetic material used is an alloy such as CoCrPt, but since the crystal anisotropy energy (Ku) is about 10 6 erg / cm 3 , the practical particle size is about 10 nm from the viewpoint of thermal fluctuation. It is believed that. In order to further reduce the particle size, it is necessary to use a magnetic material having a higher Ku. Examples of such magnetic materials include intermetallic compounds such as Co 3 Pt, CoPt, CoPt 3 , Fe 3 Pt, FePt, FePt 3 , FePd, MnBi, MnAl, SmCo 5 , and Sm 2 Co 17 , and alloys. In particular, magnetic materials such as FePt, FePd, and CoPt have a large uniaxial magnetocrystalline anisotropy in the CuAu type L1 0 ordered phase (FePt: 7 × 10 7 erg / cm 3 , CoPt: 5 × 10 7 erg / cm 3 ). Therefore, it has attracted attention as a magnetic material that solves the problem of thermal fluctuation in high-density magnetic recording.
In recent years, film formation by sputtering using these materials has been actively studied, and media having a coercive force of 10,000 Oe (796 kA / m) have been reported. However, it is difficult to narrow the particle size distribution obtained and the signal-to-noise ratio (S / N ratio) is not sufficient at present.
In recent years, synthesis in a liquid phase has been attempted in order to produce nano-sized magnetic particles having a very narrow particle size distribution. The liquid phase synthesis method is a method in which a metal salt, an organic metal or the like is dissolved in a liquid, and particles are precipitated by reduction or decomposition. Known methods for synthesizing fine particles include a coprecipitation method, a hot soap method, and a reverse micelle method.
例えばSunらは、直径が3〜10nmの範囲であるFePt磁性粒子を作る方法を報告している(非特許文献1参照)。このFePt磁性粒子は、サイズ分布の標準偏差が5%以下であり、スパッタ法によって生成される粒子のサイズ分布に比して極めて狭いのが特徴である。合成直後の粒子の結晶構造は面心立方(face-centered cubic, fcc)構造であり、550℃以上の熱処理によってL10相へと転移させる。 For example, Sun et al. Have reported a method of making FePt magnetic particles having a diameter in the range of 3 to 10 nm (see Non-Patent Document 1). This FePt magnetic particle has a standard deviation of the size distribution of 5% or less, and is characterized by being extremely narrow compared to the size distribution of particles produced by sputtering. The crystal structure of the as-synthesized particles FCC (face-centered cubic, fcc) a structure, to transfer to the L1 0 phase by heat treatment above 550 ° C..
Sunらの方法では、原料として鉄ペンタカルボニル(Fe(CO)5)と白金アセチルアセトネート(Pt(C5H7O2)2)が使用される。これらを非極性有機溶媒のオクチルエーテル中に溶解させ、不活性雰囲気中で約300℃で還流させる。ここで鉄ペンタカルボニルは分解し、カルボニルを放出してFe原子となり、白金イオンは予め添加しておいたポリオール(1,2‐ヘキサデカンジオール)により還元されて0価の白金となる。これら原子が集合して核が生成、成長し、FeとPtの合金粒子が析出する。合金の化学組成は、原料である鉄ペンタカルボニルと白金アセチルアセトネートの混合比によって調整される。また、反応過程においてオレイルアミンとオレイン酸の有機保護剤が添加されており、これらは生成されるナノ粒子の粒径制御、粒子間の凝集抑制などの重要な働きを担っている。つまり、これら有機保護剤の存在によって、析出した粒子は反応溶媒中で安定に分散した状態を保持している。 In the method of Sun et al., Iron pentacarbonyl (Fe (CO) 5 ) and platinum acetylacetonate (Pt (C 5 H 7 O 2 ) 2 ) are used as raw materials. These are dissolved in octyl ether, a nonpolar organic solvent, and refluxed at about 300 ° C. in an inert atmosphere. Here, iron pentacarbonyl is decomposed to release carbonyl to become Fe atoms, and platinum ions are reduced by a previously added polyol (1,2-hexadecanediol) to become zero-valent platinum. These atoms gather to form and grow nuclei, and alloy particles of Fe and Pt are precipitated. The chemical composition of the alloy is adjusted by the mixing ratio of the raw material iron pentacarbonyl and platinum acetylacetonate. In the reaction process, organic protective agents of oleylamine and oleic acid are added, and these play important roles such as controlling the particle size of the produced nanoparticles and suppressing aggregation between particles. That is, the presence of these organic protective agents keeps the precipitated particles stably dispersed in the reaction solvent.
しかしながら、2通りの金属析出のメカニズムを用いる上記手法は個々の粒子の化学組成の制御が困難である。これは以下の理由による。
(i)鉄カルボニルの分解温度と白金イオンの還元温度を厳密に合せるのが困難である。(ii)鉄カルボニルの沸点が103℃であるのに対し、反応温度が約300℃であるため、合成がFeソースの気化・還流を繰り返す不均一な反応系で行われる。
(iii)粒子のFeとPtの組成比と、原料のFeとPtの比率が異なる(例えば前記非特許文献1において、Fe(CO)5/Pt(C5H7O2)2=2/1の条件でFe52Pt48が得られる)。このことは、Ptの消費後に余剰のFeが粒子表面に析出したり、あるいはFe粒子が単独で析出する可能性を有している。
However, it is difficult to control the chemical composition of individual particles in the above method using two metal precipitation mechanisms. This is due to the following reason.
(I) It is difficult to strictly match the decomposition temperature of iron carbonyl and the reduction temperature of platinum ions. (Ii) The boiling point of iron carbonyl is 103 ° C., whereas the reaction temperature is about 300 ° C., so the synthesis is performed in a heterogeneous reaction system in which the Fe source is repeatedly vaporized and refluxed.
(Iii) The composition ratio of Fe and Pt of the particles and the ratio of Fe and Pt of the raw material are different (for example, in the non-patent document 1, Fe (CO) 5 / Pt (C 5 H 7 O 2 ) 2 = 2 / (Fe 52 Pt 48 is obtained under the condition 1). This has the possibility that excess Fe precipitates on the particle surface after consumption of Pt, or Fe particles precipitate alone.
L10型FePtナノ粒子の磁気特性はその化学組成に大きく依存する。L10型構造をとる化学組成は一般式FexPt1-xにおいて0.40≦x≦0.65であり、一般式FexPd1-xにおいて0.49≦x≦0.60である。この範囲外にある組成では、熱処理によっても転移が生じない。それ故、個々の粒子の組成制御は非常に重要であるが、これまでにその制御法に関する報告はない。 Magnetic properties of the L1 0 type FePt nanoparticles depends largely on its chemical composition. Chemical composition taking L1 0 type structure is 0.40 a ≦ x ≦ 0.65 in the general formula Fe x Pt 1-x, is 0.49 ≦ x ≦ 0.60 in the general formula Fe x Pd 1-x . In compositions outside this range, no transition occurs even by heat treatment. Therefore, although the composition control of individual particles is very important, there has been no report on the control method so far.
以上のように、従来の技術では、個々の粒子に着目した場合に化学組成の分布の狭いFePtあるいはFePd粒子を製造することは困難であった。この分布が広いと、加熱処理した後にL10構造に転移する粒子と転移しない粒子が同時に含まれることになり、媒体とした時の電磁変換特性を劣化させる要因となる。
本発明はこのような従来の課題に鑑みてなされたものであり、個々の粒子の化学組成の分布が狭いFePtまたはFePdナノ粒子群の製造方法を提供することを目的とする。
As described above, with the conventional technology, it is difficult to produce FePt or FePd particles having a narrow chemical composition distribution when focusing on individual particles. When the distribution is wide, will be particles which do not transfer the particles to metastasize to L1 0 structure after heat treatment occur together, it becomes a factor in deteriorating the electromagnetic conversion characteristics of the resultant medium.
This invention is made | formed in view of such a conventional subject, and it aims at providing the manufacturing method of FePt or FePd nanoparticle group with narrow distribution of the chemical composition of each particle | grain.
すなわち本発明は、FeとPtまたはFeとPdの2元合金からなるナノ粒子群の製造方法であって、
(a)非極性有機溶剤中に鉄ペンタカルボニルと、PtまたはPdの錯体とを、前記PtまたはPdの錯体1モルに対し、0.01〜0.4モルの有機保護剤の存在下、不活性雰囲気中で溶解させるステップと、
(b)不活性雰囲気中、230℃以上で加熱を行ってFePtあるいはFePd合金ナノ粒子を生成するステップとからなり、
FexM1-x(式中、MはPtまたはPdを表し、xは、MがPtの時、0.40≦x≦0.65であり、MがPdの時、0.49≦x≦0.60である。)で表される組成を有する粒子が全体の60%以上含まれ、かつ平均粒径が2〜10nmの範囲内であるナノ粒子群を製造することを特徴とするナノ粒子群の製造方法である。
ここで、前記ナノ粒子群の製造方法は、還元剤を添加せずに行われることが望ましい。
That is, the present invention is a method for producing nanoparticles comprising a binary alloy of Fe and Pt or Fe and Pd,
(a) In a nonpolar organic solvent, iron pentacarbonyl and a complex of Pt or Pd are added in the presence of 0.01 to 0.4 mol of an organic protective agent with respect to 1 mol of the Pt or Pd complex. Dissolving in an active atmosphere;
(b) heating at 230 ° C. or higher in an inert atmosphere to generate FePt or FePd alloy nanoparticles,
Fe x M 1-x (wherein M represents Pt or Pd, x is 0.40 ≦ x ≦ 0.65 when M is Pt, and 0.49 ≦ x when M is Pd) ≦ 0.60.) A nanoparticle group comprising 60% or more of particles having a composition represented by the formula (1) and having an average particle diameter in the range of 2 to 10 nm. It is a manufacturing method of a particle group.
Here, it is preferable that the manufacturing method of the nanoparticle group is performed without adding a reducing agent.
前記Ptの錯体としては、白金エチレンジアミン錯体、白金トリエチルホスフィン錯体、白金トリフェニルホスフィン錯体、白金アンミン錯体及び白金(II)アセチルアセトネートからなる群から選ばれる少なくとも一種の白金化合物であり、
前記Pdの錯体は、パラジウムトリフェニルホスフィン錯体、パラジウムアンミン錯体、パラジウムエチレンジアミン錯体及びパラジウムアセチルアセトネートからなる群から選ばれる少なくとも一種のパラジウム化合物であることが好ましい。
The Pt complex is at least one platinum compound selected from the group consisting of a platinum ethylenediamine complex, a platinum triethylphosphine complex, a platinum triphenylphosphine complex, a platinum ammine complex and platinum (II) acetylacetonate,
The Pd complex is preferably at least one palladium compound selected from the group consisting of a palladium triphenylphosphine complex, a palladium ammine complex, a palladium ethylenediamine complex, and palladium acetylacetonate.
また、前記有機保護剤は、式:R−X(式中、Rは5〜22個の炭素原子を含む直鎖または分岐炭化水素鎖、芳香族炭化水素鎖およびシクロヘキサン環からなる群から選択される基であり、Xはカルボン酸、ホスホン酸、ホスフィン酸、ホスフィン、スルホン酸、スルフィン酸およびアミンからなる群から選択される基である。)
で表される有機化合物の少なくとも一種を含むことが好ましい。
The organic protective agent is selected from the group consisting of the formula: R—X (wherein R is a linear or branched hydrocarbon chain containing 5 to 22 carbon atoms, an aromatic hydrocarbon chain, and a cyclohexane ring). X is a group selected from the group consisting of carboxylic acid, phosphonic acid, phosphinic acid, phosphine, sulfonic acid, sulfinic acid and amine.)
It is preferable that at least 1 type of the organic compound represented by these is included.
さらに本発明によれば、上記の方法で製造されたFeとPtまたはFeとPdの2元合金からなるナノ粒子群であって、
FexM1-x(式中、MはPtまたはPdを表し、MがPtの時、0.40≦x≦0.65であり、MがPdの時、0.49≦x≦0.60である。)で表される組成を有する粒子が全体の60%以上含まれ、かつ平均粒径が2〜10nmの範囲内であることを特徴とするナノ粒子群が提供される。
ここで、ナノ粒子群は、熱処理によりL10規則相を発現するものであることを好適とする。ナノ粒子がL10規則相を発現することで、大きな一軸結晶磁気異方性を示す磁気材料として用いることができる。
Furthermore, according to the present invention, there is a group of nanoparticles composed of a binary alloy of Fe and Pt or Fe and Pd manufactured by the above method,
Fe x M 1-x (wherein M represents Pt or Pd, and when M is Pt, 0.40 ≦ x ≦ 0.65, and when M is Pd, 0.49 ≦ x ≦ 0. 60).) A group of nanoparticles is provided, wherein 60% or more of the particles having a composition represented by the formula (1) are contained and the average particle size is in the range of 2 to 10 nm.
Here, nanoparticle group, and preferably it is intended to express the L1 0 ordered phase by heat treatment. When the nanoparticles exhibit an L1 0 ordered phase, they can be used as a magnetic material exhibiting a large uniaxial crystal magnetic anisotropy.
本発明によれば、FePtあるいはFePd合金ナノ粒子において、粒子間のFeとPtまたはPdの元素含有比の分布が小さい粒子を作製することが可能である。このため、この粒子は熱処理によりそのほとんどがL10規則相を発現し、電磁変換特性の優れた媒体が得られる。 According to the present invention, in FePt or FePd alloy nanoparticles, it is possible to produce particles having a small distribution of Fe and Pt or Pd element content ratio between the particles. For this reason, most of the particles exhibit an L10 ordered phase by heat treatment, and a medium having excellent electromagnetic conversion characteristics can be obtained.
以下に、本発明の実施の形態について説明する。
本発明によるナノ粒子群の製造方法は、
(a)非極性有機溶剤中に鉄ペンタカルボニルと、PtまたはPdの錯体とを、前記PtまたはPdの錯体1モルに対し、0.01〜0.4モルの有機保護剤の存在下、不活性雰囲気中で溶解させるステップと、
(b)不活性雰囲気中、230℃以上で加熱を行ってFePtあるいはFePd合金ナノ粒子を生成するステップと
によって製造することができる。
Embodiments of the present invention will be described below.
The method for producing nanoparticles according to the present invention includes:
(a) In a nonpolar organic solvent, iron pentacarbonyl and a complex of Pt or Pd are added in the presence of 0.01 to 0.4 mol of an organic protective agent with respect to 1 mol of the Pt or Pd complex. Dissolving in an active atmosphere;
(b) heating at 230 ° C. or higher in an inert atmosphere to produce FePt or FePd alloy nanoparticles.
まず、(a)ステップについて説明する。
本発明で用いられるPtまたはPdの錯体としては、Ptの錯体として、白金エチレンジアミン錯体、白金トリエチルホスフィン錯体、白金トリフェニルホスフィン錯体、白金アンミン錯体及び白金(II)アセチルアセトネートからなる群から選ばれる少なくとも一種の白金化合物が挙げられる。また、Pdの錯体としては、パラジウムトリフェニルホスフィン錯体、パラジウムアンミン錯体、パラジウムエチレンジアミン錯体及びパラジウムアセチルアセトネートからなる群から選ばれる少なくとも一種のパラジウム化合物が挙げられる。これら錯体は単独で用いることもできるし、2つ以上が混合されて用いられても良い。
First, step (a) will be described.
The Pt or Pd complex used in the present invention is selected from the group consisting of a platinum ethylenediamine complex, a platinum triethylphosphine complex, a platinum triphenylphosphine complex, a platinum ammine complex, and platinum (II) acetylacetonate. There may be mentioned at least one platinum compound. Examples of the Pd complex include at least one palladium compound selected from the group consisting of a palladium triphenylphosphine complex, a palladium ammine complex, a palladium ethylenediamine complex, and palladium acetylacetonate. These complexes can be used alone or in combination of two or more.
本発明の方法におけるPtまたはPdの錯体の濃度は、0.5mmol/ml以下であることが好ましい。
また、鉄ペンタカルボニルの使用量は、モル比で、鉄ペンタカルボニル/(PtまたはPdの錯体)=1.5〜3.0となるような量が好ましい。
The concentration of Pt or Pd complex in the method of the present invention is preferably 0.5 mmol / ml or less.
The amount of iron pentacarbonyl used is preferably such that the molar ratio is iron pentacarbonyl / (Pt or Pd complex) = 1.5 to 3.0.
本発明で用いられる有機保護剤としては、式:R−X(式中、Rは5〜22個の炭素原子を含む直鎖または分岐炭化水素鎖、芳香族炭化水素鎖およびシクロヘキサン環からなる群から選択される基であり、Xはカルボン酸、ホスホン酸、ホスフィン酸、ホスフィン、スルホン酸、スルフィン酸およびアミンからなる群から選択される基である。)
で表される有機化合物の少なくとも一種であることが望ましい。
The organic protective agent used in the present invention includes a group represented by the formula: R—X (wherein R is a linear or branched hydrocarbon chain containing 5 to 22 carbon atoms, an aromatic hydrocarbon chain, and a cyclohexane ring). X is a group selected from the group consisting of carboxylic acid, phosphonic acid, phosphinic acid, phosphine, sulfonic acid, sulfinic acid and amine.)
It is desirable that it is at least one of the organic compounds represented by
有機保護剤は金属粒子の表面に配位結合することで、金属粒子の成長速度、すなわち、粒子径を制御する働きを担っている。また有機保護剤層は粒子に吸着し立体障害層として寄与し、粒子表面間の直接の接触を防ぐことにより多結晶化するのを防止することが可能である。粒子は有機保護剤の式:R−Xにおける炭素数が5個未満であると非極性有機溶媒に対する溶解性が悪くなる。一方、22個を超えるとその効果は飽和する。これら有機保護剤は単独で用いてもよく、あるいは複数で用いてもよい。 The organic protective agent has a function of controlling the growth rate of the metal particles, that is, the particle diameter, by coordination bonding to the surface of the metal particles. Further, the organic protective agent layer is adsorbed on the particles and contributes as a steric hindrance layer, and can be prevented from being polycrystallized by preventing direct contact between the particle surfaces. When the particle has less than 5 carbon atoms in the formula R—X of the organic protective agent, the solubility in the nonpolar organic solvent becomes poor. On the other hand, when it exceeds 22, the effect is saturated. These organic protective agents may be used alone or in combination.
有機保護剤の添加量は、PtまたはPdの錯体1モルに対し、0.01〜0.4モルである。この範囲であれば、後述する(b)ステップにおいて析出した粒子は有機保護剤の不足により十分な斥力を得ることができず凝集し、沈殿を生じる。沈殿生成を反応の終点とし、速やかに冷却することにより、余剰の鉄ペンタカルボニルが分解した鉄原子が粒子表面で析出し、コア−シェル構造となることを抑制することが可能である。なお、この沈殿は永久的な凝集体ではなく、前述のように、有機保護剤が障害層となり、粒子表面の直接の接触を防ぐため、反応時と同種あるいは前記記載の有機化合物を添加することにより、非極性溶媒中に分散させることが可能である。 The addition amount of the organic protective agent is 0.01 to 0.4 mol with respect to 1 mol of the Pt or Pd complex. Within this range, the particles precipitated in the step (b) described later cannot be obtained a sufficient repulsive force due to the lack of the organic protective agent, and are aggregated to cause precipitation. By setting the precipitation as the end point of the reaction and rapidly cooling, it is possible to suppress the iron atoms in which the excess iron pentacarbonyl is decomposed from being precipitated on the particle surface and forming a core-shell structure. In addition, this precipitation is not a permanent aggregate, and as described above, the organic protective agent becomes an obstacle layer, and in order to prevent direct contact with the particle surface, the same kind as in the reaction or the organic compound described above should be added. Thus, it can be dispersed in a nonpolar solvent.
有機保護剤の添加量が0.01モルより少ない場合には、永久凝集を起こす粒子の割合が高くなり、歩留まりが低下する。逆に0.4モルよりも多い場合には、析出した粒子は安定な分散状態を保持するため、粒子表面に鉄の多い層が形成されやすく、全体として組成の分布が大きくなることに繋がる。 When the amount of the organic protective agent added is less than 0.01 mol, the proportion of particles that cause permanent aggregation increases and the yield decreases. On the other hand, when the amount is more than 0.4 mol, the precipitated particles maintain a stable dispersion state, so that a layer containing iron is easily formed on the surface of the particles, leading to an increase in the distribution of the composition as a whole.
本発明で用いられる非極性有機溶媒は高沸点のもので、例えばジドデシルエーテル、ジオクチルエーテル、フェニルエーテル、ベンジルエーテル、ベンジルフェニルエーテルなどが挙げられる。 The nonpolar organic solvent used in the present invention has a high boiling point, and examples thereof include didodecyl ether, dioctyl ether, phenyl ether, benzyl ether, and benzyl phenyl ether.
次に、(b)ステップについて説明する。
(b)ステップにおける加熱温度は230℃以上であることが必要である。加熱温度が230℃未満であると、Feの分解速度が低いため、Feの含有量にばらつきが生じる。加熱温度の上限は、特に規定はされないが、350℃以上では有機物が分解するおそれがあるため、350℃以下であることが好ましい。
Next, step (b) will be described.
The heating temperature in step (b) needs to be 230 ° C. or higher. When the heating temperature is less than 230 ° C., the Fe decomposition rate is low, and thus the Fe content varies. The upper limit of the heating temperature is not particularly specified, but is preferably 350 ° C. or lower because organic substances may be decomposed at 350 ° C. or higher.
また、本発明ではPtあるいはPdのイオンを還元するための還元剤は用いない。これらイオンは鉄ペンタカルボニルから放出されるCO(カルボニル)によって還元される。 In the present invention, a reducing agent for reducing Pt or Pd ions is not used. These ions are reduced by CO (carbonyl) released from iron pentacarbonyl.
本発明のナノ微粒子の合成は、微粒子の酸化を防止し、かつ合成中にFe(CO)5が反応系外に排出されるのを防ぐために、窒素あるいはAr等の不活性ガスにより陽圧にした不活性雰囲気中で行われる。 The synthesis of the nano-particles of the present invention is carried out at a positive pressure with an inert gas such as nitrogen or Ar in order to prevent oxidation of the particles and to prevent Fe (CO) 5 from being discharged out of the reaction system during the synthesis. In an inert atmosphere.
前述したように、有機保護剤の添加量を本発明の範囲としたことにより、加熱により析出した粒子は有機保護剤の不足により十分な斥力を得ることができず凝集し、沈殿を生じる。沈殿生成を反応の終点とし、速やかに冷却することにより、余剰の鉄ペンタカルボニルが分解した鉄原子が粒子表面で析出し、コア−シェル構造となることが抑制される。この沈殿は永久的な凝集体ではなく、反応時と同種あるいは前記記載の有機化合物を添加することにより、非極性溶媒中に分散させることが可能である。 As described above, by setting the addition amount of the organic protective agent within the range of the present invention, particles precipitated by heating cannot obtain a sufficient repulsive force due to a shortage of the organic protective agent, and aggregate to cause precipitation. By using the precipitation generation as the end point of the reaction and rapidly cooling, it is possible to suppress the iron atoms in which excess iron pentacarbonyl is decomposed from being precipitated on the surface of the particles and forming a core-shell structure. This precipitate is not a permanent aggregate, but can be dispersed in a nonpolar solvent by adding the same kind of organic compound as in the reaction or the organic compound described above.
上記した方法により、FexM1-x(式中、MはPtまたはPdを表し、xは、MがPtの時、0.40≦x≦0.65であり、MがPdの時、0.49≦x≦0.60である。)で表される組成を有する粒子が全体の60%以上含まれ、かつ平均粒径が2〜10nmの範囲内であるナノ粒子群を得ることができる。ここで、FexM1-xにおけるxは鉄ペンタカルボニルとPt錯体またはPd錯体の比率を変えることによって任意に変えることができる。xが上記の範囲をとることで、熱処理した時にL10規則相を発現する。またこのL10規則相を発現することで、大きな一軸結晶磁気異方性を示す磁気材料として用いることができる。 According to the above method, Fe x M 1-x (wherein M represents Pt or Pd, x is 0.40 ≦ x ≦ 0.65 when M is Pt, and when M is Pd, 0.49 ≦ x ≦ 0.60.) To obtain a nanoparticle group in which particles having a composition represented by the formula: 60% or more of the whole are contained and the average particle size is in the range of 2 to 10 nm. it can. Here, x in Fe x M 1-x can be arbitrarily changed by changing the ratio of iron pentacarbonyl to Pt complex or Pd complex. When x is in the above range, an L1 0 ordered phase is developed when heat treatment is performed. Further, by expressing this L1 0 ordered phase, it can be used as a magnetic material exhibiting a large uniaxial crystal magnetic anisotropy.
また、粒子の粒度分布を極めて狭いものとするために、得られたナノ粒子群は公知の方法で選択的サイズ分級を行うことができる。例えば界面活性剤で被覆された金属ナノ粒子を非極性溶媒中に分散させ、極性溶媒(例えばアルコール、ケトン)を加えることによって元の分布から単分散成分を抽出する。これによって粒度分布の標準偏差を好ましくは10%以下、更に好ましくは5%以下にする。 Moreover, in order to make the particle size distribution of the particles extremely narrow, the obtained nanoparticle group can be subjected to selective size classification by a known method. For example, metal nanoparticles coated with a surfactant are dispersed in a nonpolar solvent, and a monodisperse component is extracted from the original distribution by adding a polar solvent (eg, alcohol, ketone). Thus, the standard deviation of the particle size distribution is preferably 10% or less, more preferably 5% or less.
得られたナノ粒子群から磁気記録媒体を作成する方法としては、従来公知のいかなる方法も適用できる。例えば、基板上にシランカップリング剤であるAPTS([3-(2-aminoethylamino)propyl]trimethoxysilane)よりなる層を形成し、その上にナノ粒子分散溶液を接触させ、乾燥後、熱処理する方法は、結晶構造を転移させるための熱処理時に粒子間焼結を抑制できるというメリットがあるため、好ましい方法の一つである。 As a method for producing a magnetic recording medium from the obtained nanoparticle group, any conventionally known method can be applied. For example, a method of forming a layer made of APTS ([3- (2-aminoethylamino) propyl] trimethoxysilane), which is a silane coupling agent, on a substrate, bringing a nanoparticle dispersion solution into contact therewith, drying, and heat-treating is as follows. This is one of the preferred methods because of the merit that inter-particle sintering can be suppressed during the heat treatment for transferring the crystal structure.
得られたナノ粒子群は、熱処理することによりL10規則相を発現する。熱処理温度は400〜800℃が好ましい。処理温度がこれより低い場合には、L10層への転移が不完全であり、一方、処理温度が800℃よりも高い場合には、基板から他元素が拡散し、磁気特性が劣化する恐れ等があり不適である。 The resulting nano-particles expresses an L1 0 ordered phase by heat treatment. The heat treatment temperature is preferably 400 to 800 ° C. If the treatment temperature is lower than this is incomplete transition to L1 0 layer, whereas, if the processing temperature is higher than 800 ° C., the other element is diffused from the substrate, the magnetic characteristics are deteriorated risk Etc. are inappropriate.
以下、実施例に基づき本発明の内容を説明するが、本発明はこの実施例に限定されるものではないことは言うまでもない。 Hereinafter, although the content of the present invention will be described based on examples, it goes without saying that the present invention is not limited to these examples.
(実施例1)
ジオクチルエーテル(沸点:297℃)40mlに鉄ペンタカルボニル2mmol、白金(II)アセチルアセトネートを1mmol、オレイン酸0.1mmol、オレイルアミン0.1mmolを加え、窒素雰囲気下で攪拌しながら還流した。溶液が黒色に変化した後に10分間保持し、速やかに冷却した。室温まで冷却した後、エタノールを加え、遠心分離を行い黒色の沈殿を得た。これにヘキサンを加え、オレイルアミン及びオレイン酸を各々0.5mmol加え、FePtナノ粒子の分散液を得た。得られたFePtナノ粒子の分散液を透過型電子顕微鏡(TEM)観察用のグリッドに載せ、乾燥後、FePtナノ粒子のTEM像を測定した。その結果を図1に示す。TEM像から粒子の平均粒径は4.2nmであることがわかった。
(Example 1)
To 40 ml of dioctyl ether (boiling point: 297 ° C.), 2 mmol of iron pentacarbonyl, 1 mmol of platinum (II) acetylacetonate, 0.1 mmol of oleic acid and 0.1 mmol of oleylamine were added and refluxed with stirring under a nitrogen atmosphere. After the solution turned black, it was held for 10 minutes and quickly cooled. After cooling to room temperature, ethanol was added and centrifuged to obtain a black precipitate. Hexane was added thereto, and 0.5 mmol each of oleylamine and oleic acid was added to obtain a dispersion of FePt nanoparticles. The obtained dispersion of FePt nanoparticles was placed on a grid for observation with a transmission electron microscope (TEM), and after drying, a TEM image of FePt nanoparticles was measured. The result is shown in FIG. From the TEM image, it was found that the average particle diameter of the particles was 4.2 nm.
(実施例2)
ジオクチルエーテル(沸点:297℃)40mlに鉄ペンタカルボニル2mmol、白金(II)アセチルアセトネートを1mmol、オレイン酸0.01mmol、オレイルアミン0.01mmolを加え、窒素雰囲気下で攪拌しながら還流した。溶液が黒色に変化した後に10分間保持し、速やかに冷却した。室温まで冷却した後、エタノールを加え、遠心分離を行い黒色の沈殿を得た。これにヘキサンを加え、オレイルアミン及びオレイン酸を各々0.5mmol加え、FePtナノ粒子の分散液を得た。
(Example 2)
To 40 ml of dioctyl ether (boiling point: 297 ° C.) were added 2 mmol of iron pentacarbonyl, 1 mmol of platinum (II) acetylacetonate, 0.01 mmol of oleic acid, and 0.01 mmol of oleylamine, and the mixture was refluxed with stirring under a nitrogen atmosphere. After the solution turned black, it was held for 10 minutes and quickly cooled. After cooling to room temperature, ethanol was added and centrifuged to obtain a black precipitate. Hexane was added thereto, and 0.5 mmol each of oleylamine and oleic acid was added to obtain a dispersion of FePt nanoparticles.
(実施例3)
ジオクチルエーテル(沸点:297℃)40mlに鉄ペンタカルボニル2mmol、白金(II)アセチルアセトネートを1mmol、オレイン酸0.2mmol、オレイルアミン0.2mmolを加え、窒素雰囲気下で攪拌しながら還流した。溶液が黒色に変化した後に10分間保持し、速やかに冷却した。室温まで冷却した後、エタノールを加え、遠心分離を行い黒色の沈殿を得た。これにヘキサンを加え、オレイルアミン及びオレイン酸を各々0.5mmol加え、FePtナノ粒子の分散液を得た。
(Example 3)
To 40 ml of dioctyl ether (boiling point: 297 ° C.) were added 2 mmol of iron pentacarbonyl, 1 mmol of platinum (II) acetylacetonate, 0.2 mmol of oleic acid, and 0.2 mmol of oleylamine, and the mixture was refluxed with stirring under a nitrogen atmosphere. After the solution turned black, it was held for 10 minutes and quickly cooled. After cooling to room temperature, ethanol was added and centrifuged to obtain a black precipitate. Hexane was added thereto, and 0.5 mmol each of oleylamine and oleic acid was added to obtain a dispersion of FePt nanoparticles.
(実施例4)
ジオクチルエーテル(沸点:297℃)20ml、ジフェニルエーテル(沸点:259℃)20mlの混合溶媒に鉄ペンタカルボニル2mmol、白金(II)アセチルアセトネートを1mmol、オレイン酸0.1mmol、オレイルアミン0.1mmolを加え、窒素雰囲気下で250℃で攪拌しながら加熱した。溶液が黒色に変化した後に10分間保持し、速やかに冷却した。室温まで冷却した後、エタノールを加え、遠心分離を行い黒色の沈殿を得た。これにヘキサンを加え、オレイルアミン及びオレイン酸を各々0.5mmol加え、FePtナノ粒子の分散液を得た。
Example 4
To a mixed solvent of 20 ml of dioctyl ether (boiling point: 297 ° C.) and 20 ml of diphenyl ether (boiling point: 259 ° C.) was added 2 mmol of iron pentacarbonyl, 1 mmol of platinum (II) acetylacetonate, 0.1 mmol of oleic acid, 0.1 mmol of oleylamine, The mixture was heated with stirring at 250 ° C. under a nitrogen atmosphere. After the solution turned black, it was held for 10 minutes and quickly cooled. After cooling to room temperature, ethanol was added and centrifuged to obtain a black precipitate. Hexane was added thereto, and 0.5 mmol each of oleylamine and oleic acid was added to obtain a dispersion of FePt nanoparticles.
(実施例5)
ジオクチルエーテル(沸点:297℃)40mlに鉄ペンタカルボニル2mmol、白金(II)アセチルアセトネートを1mmol、ステアリン酸0.1mmol、オレイルアミン0.1mmolを加え、窒素雰囲気下で攪拌しながら230℃で加熱した。溶液が黒色に変化した後に10分間保持し、速やかに冷却した。室温まで冷却した後、エタノールを加え、遠心分離を行い黒色の沈殿を得た。これにヘキサンを加え、オレイルアミン及びオレイン酸を各々0.5mmol加え、FePtナノ粒子の分散液を得た。
(Example 5)
To 40 ml of dioctyl ether (boiling point: 297 ° C.) was added 2 mmol of iron pentacarbonyl, 1 mmol of platinum (II) acetylacetonate, 0.1 mmol of stearic acid and 0.1 mmol of oleylamine, and the mixture was heated at 230 ° C. with stirring in a nitrogen atmosphere. . After the solution turned black, it was held for 10 minutes and quickly cooled. After cooling to room temperature, ethanol was added and centrifuged to obtain a black precipitate. Hexane was added thereto, and 0.5 mmol each of oleylamine and oleic acid was added to obtain a dispersion of FePt nanoparticles.
(実験例1)
ジオクチルエーテル(沸点:297℃)40mlに鉄ペンタカルボニル2mmol、白金(II)アセチルアセトネートを1mmol、オレイン酸0.003mmol、オレイルアミン0.003mmolを加え、窒素雰囲気下で攪拌しながら還流した。溶液が黒色に変化した後に10分間保持し、速やかに冷却した。室温まで冷却した後、エタノールを加え、遠心分離を行い黒色の沈殿を得た。これにヘキサンを加え、オレイルアミン及びオレイン酸を各々0.5mmol加え、FePtナノ粒子の分散液を得た。ただし、析出粒子に対し分散粒子の割合が50%であった。
(Experiment 1)
To 40 ml of dioctyl ether (boiling point: 297 ° C.) were added 2 mmol of iron pentacarbonyl, 1 mmol of platinum (II) acetylacetonate, 0.003 mmol of oleic acid, and 0.003 mmol of oleylamine, and the mixture was refluxed with stirring in a nitrogen atmosphere. After the solution turned black, it was held for 10 minutes and quickly cooled. After cooling to room temperature, ethanol was added and centrifuged to obtain a black precipitate. Hexane was added thereto, and 0.5 mmol each of oleylamine and oleic acid was added to obtain a dispersion of FePt nanoparticles. However, the ratio of dispersed particles to precipitated particles was 50%.
(実験例2)
ジオクチルエーテル(沸点:297℃)40mlに鉄ペンタカルボニル2mmol、白金(II)アセチルアセトネートを1mmol、オレイン酸0.5mmol、オレイルアミン0.5mmolを加え、窒素雰囲気下で攪拌しながら還流した。溶液が黒色に変化した後に10分間保持し、速やかに冷却した。この際、粒子は溶液中で分散状態が保持されている。室温まで冷却した後、エタノールを加え、遠心分離を行い黒色の沈殿を得た。これにヘキサンを加え、FePtナノ粒子の分散液を得た。
(Experimental example 2)
To 40 ml of dioctyl ether (boiling point: 297 ° C.) were added 2 mmol of iron pentacarbonyl, 1 mmol of platinum (II) acetylacetonate, 0.5 mmol of oleic acid, and 0.5 mmol of oleylamine, and the mixture was refluxed with stirring under a nitrogen atmosphere. After the solution turned black, it was held for 10 minutes and quickly cooled. At this time, the particles are kept dispersed in the solution. After cooling to room temperature, ethanol was added and centrifuged to obtain a black precipitate. Hexane was added thereto to obtain a dispersion of FePt nanoparticles.
(実験例3)
ジオクチルエーテル(沸点:297℃)40mlに鉄ペンタカルボニル2mmol、白金(II)アセチルアセトネートを1mmol、オレイン酸0.1mmol、オレイルアミン0.1mmolを加え、更に1,2‐ヘキサデカンジオールを3mmol加え、窒素雰囲気下で攪拌しながら還流した。溶液が黒色に変化した後に10分間保持し、速やかに冷却した。室温まで冷却した後、エタノールを加え、遠心分離を行い黒色の沈殿を得た。これにヘキサンを加え、オレイルアミン及びオレイン酸を各々0.5mmol加え、FePtナノ粒子の分散液を得た。
(Experimental example 3)
To 40 ml of dioctyl ether (boiling point: 297 ° C.), 2 mmol of iron pentacarbonyl, 1 mmol of platinum (II) acetylacetonate, 0.1 mmol of oleic acid, 0.1 mmol of oleylamine, and 3 mmol of 1,2-hexadecanediol are added. The mixture was refluxed with stirring under an atmosphere. After the solution turned black, it was held for 10 minutes and quickly cooled. After cooling to room temperature, ethanol was added and centrifuged to obtain a black precipitate. Hexane was added thereto, and 0.5 mmol each of oleylamine and oleic acid was added to obtain a dispersion of FePt nanoparticles.
(実験例4)
ジオクチルエーテル(沸点:297℃)40mlに鉄ペンタカルボニル2mmol、白金(II)アセチルアセトネートを1mmol、オレイン酸0.1mmol、オレイルアミン0.1mmolを加え、窒素雰囲気下で攪拌しながら200℃で加熱した。溶液が黒色に変化した後に10分間保持し、速やかに冷却した。室温まで冷却した後、エタノールを加え、遠心分離を行い黒色の沈殿を得た。これにヘキサンを加え、オレイルアミン及びオレイン酸を各々0.5mmol加え、FePtナノ粒子の分散液を得た。
(Experimental example 4)
To 40 ml of dioctyl ether (boiling point: 297 ° C.) was added 2 mmol of iron pentacarbonyl, 1 mmol of platinum (II) acetylacetonate, 0.1 mmol of oleic acid and 0.1 mmol of oleylamine, and the mixture was heated at 200 ° C. with stirring in a nitrogen atmosphere. . After the solution turned black, it was held for 10 minutes and quickly cooled. After cooling to room temperature, ethanol was added and centrifuged to obtain a black precipitate. Hexane was added thereto, and 0.5 mmol each of oleylamine and oleic acid was added to obtain a dispersion of FePt nanoparticles.
実施例1〜5及び実験例1〜4で得られたFePtナノ粒子の平均粒子径と平均化学組成、及び粒子をFexPt1-xとした時、粒子全体に対する0.40≦x≦0.65となる粒子の割合を表1に示す。 The average particle diameter and average chemical composition of the FePt nanoparticles obtained in Examples 1 to 5 and Experimental Examples 1 to 4, and 0.40 ≦ x ≦ 0 with respect to the entire particle when the particles are Fe x Pt 1-x Table 1 shows the ratio of particles to be .65.
ここで、平均化学組成とは、粒子全体としての組成を意味し、X線マイクロアナライザにより10μmx10μmのエリア3点について求めた値の平均値である。また、個々の粒子の化学組成の分布は高分解TEMに設置されたエネルギー分散型X線分析装置(EDX)により任意の10粒子についてその各元素含有量を分析することにより求めた。一例として、実施例1のTEM‐EDXによる粒子の元素含有量分析結果を表2に示す。
なお、結晶構造は何れの場合も面心立方構造であった。分散粒子の収率は実験例1を除き、約80%であった。
Here, the average chemical composition means the composition of the whole particle, and is an average value of values obtained for three areas of 10 μm × 10 μm by an X-ray microanalyzer. In addition, the distribution of the chemical composition of each particle was determined by analyzing the content of each element for any 10 particles using an energy dispersive X-ray analyzer (EDX) installed in a high resolution TEM. As an example, Table 2 shows the element content analysis results of the particles by TEM-EDX of Example 1.
In all cases, the crystal structure was a face-centered cubic structure. The yield of dispersed particles was about 80%, except for Experimental Example 1.
表1に示すように本発明による製造方法を採用した実施例1〜5では粒子の化学組成がFexPt1-xにおいて0.40≦x≦0.65である割合が60%以上である粒子が得られた。一方、有機保護剤がPt錯体1molに対し0.01molよりも少ない条件で合成した実験例1は0.40≦x≦0.65となる粒子が60%以上であったが、凝集体の占める割合が多く、収率が低い。実験例2及び実験例4は本発明の製造条件から外れた条件で行った実験の例であるが、組成の分布が大きい結果となった。実験例3は還元剤として1,2−ヘキサデカンジオールを添加した例であるが、この場合も、粒子間の組成の分布を狭くすることはできない。 As shown in Table 1, in Examples 1 to 5 employing the production method according to the present invention, the proportion of the chemical composition of the particles in Fe x Pt 1-x is 0.40 ≦ x ≦ 0.65 is 60% or more. Particles were obtained. On the other hand, in Experimental Example 1 in which the organic protective agent was synthesized under a condition of less than 0.01 mol with respect to 1 mol of the Pt complex, the particles satisfying 0.40 ≦ x ≦ 0.65 were 60% or more. The ratio is large and the yield is low. Experimental Example 2 and Experimental Example 4 are examples of experiments conducted under conditions deviating from the production conditions of the present invention, but the results showed a large composition distribution. Experimental Example 3 is an example in which 1,2-hexadecanediol is added as a reducing agent, but also in this case, the distribution of the composition between the particles cannot be narrowed.
実施例1で合成されたFePt粒子を用いて粒子群の磁気特性を測定した。Si基板上にシランカップリング剤であるAPTS([3-(2-aminoethylamino)propyl]trimethoxysilane)よりなる層を形成し、その上にナノ粒子分散溶液を接触させ、乾燥後、真空下、800℃で熱処理した粒子群の磁気特性を測定した結果、5Kにおいて11 kOe(876kA/m)の保磁力を有することがわかった。結晶構造を面内X線回折スペクトル(in-plane XRD)により測定し、L10型構造への転移が確認された。 Using the FePt particles synthesized in Example 1, the magnetic properties of the particles were measured. A layer made of APTS ([3- (2-aminoethylamino) propyl] trimethoxysilane), which is a silane coupling agent, is formed on a Si substrate, and a nanoparticle dispersion solution is brought into contact therewith, dried, and then at 800 ° C. under vacuum. As a result of measuring the magnetic properties of the particle group heat-treated in Step 1, it was found that the particles had a coercive force of 11 kOe (876 kA / m) at 5K. The crystal structure was determined by in-plane X-ray diffraction spectrum (in-plane XRD), transfer to L1 0 type structure was confirmed.
(実施例6)
ジオクチルエーテル(沸点:297℃)40mlに鉄ペンタカルボニル2mmol、パラジウム(II)アセチルアセトネートを1mmol、オレイン酸0.1mmol、オレイルアミン0.1mmolを加え、窒素雰囲気下で攪拌しながら還流した。溶液が黒色に変化した後に10分間保持し、速やかに冷却した。室温まで冷却した後、エタノールを加え、遠心分離を行い黒色の沈殿を得た。これにヘキサンを加え、オレイルアミン及びオレイン酸を各々0.5mmol加え、FePdナノ粒子の分散液を得た。
実施例1と同様にして測定したナノ粒子の平均粒子径は4.0nmであり、平均化学組成はFe51Pd49であった。また、FexPd1-xにおいて0.49≦x≦0.60の粒子の含有率は70%であった。
(Example 6)
To 40 ml of dioctyl ether (boiling point: 297 ° C.) were added 2 mmol of iron pentacarbonyl, 1 mmol of palladium (II) acetylacetonate, 0.1 mmol of oleic acid, and 0.1 mmol of oleylamine, and the mixture was refluxed with stirring under a nitrogen atmosphere. After the solution turned black, it was held for 10 minutes and quickly cooled. After cooling to room temperature, ethanol was added and centrifuged to obtain a black precipitate. Hexane was added thereto, and 0.5 mmol each of oleylamine and oleic acid was added to obtain a dispersion of FePd nanoparticles.
The average particle diameter of the nanoparticles measured in the same manner as in Example 1 was 4.0 nm, and the average chemical composition was Fe 51 Pd 49 . The content of 0.49 ≦ x ≦ 0.60 for the particles in Fe x Pd 1-x was 70%.
(実施例7)
ジオクチルエーテル(沸点:297℃)40mlに鉄ペンタカルボニル2mmol、白金(II)アセチルアセトネートを1mmol、オレイン酸0.005mmol、オレイルアミン0.005mmolを加え、窒素雰囲気下で攪拌しながら還流した。溶液が黒色に変化した後に10分間保持し、速やかに冷却した。室温まで冷却した後、エタノールを加え、遠心分離を行い黒色の沈殿を得た。これにヘキサンを加え、オレイルアミン及びオレイン酸を各々0.5mmol加え、FePtナノ粒子の分散液を得た。
実施例1と同様にして測定したナノ粒子の平均粒子径は4.3nmであり、平均化学組成はFe52Pt48であった。また、FexPt1-xにおいて0.40≦x≦0.65の粒子の含有率は60%であった。
(Example 7)
To 40 ml of dioctyl ether (boiling point: 297 ° C.), 2 mmol of iron pentacarbonyl, 1 mmol of platinum (II) acetylacetonate, 0.005 mmol of oleic acid and 0.005 mmol of oleylamine were added and refluxed with stirring under a nitrogen atmosphere. After the solution turned black, it was held for 10 minutes and quickly cooled. After cooling to room temperature, ethanol was added and centrifuged to obtain a black precipitate. Hexane was added thereto, and 0.5 mmol each of oleylamine and oleic acid was added to obtain a dispersion of FePt nanoparticles.
The average particle diameter of the nanoparticles measured in the same manner as in Example 1 was 4.3 nm, and the average chemical composition was Fe 52 Pt 48 . In addition, the content ratio of particles of 0.40 ≦ x ≦ 0.65 in Fe x Pt 1-x was 60%.
Claims (6)
(a)非極性有機溶剤中に鉄ペンタカルボニルと、PtまたはPdの錯体とを、前記PtまたはPdの錯体1モルに対し、0.01〜0.4モルの有機保護剤の存在下、不活性雰囲気中で溶解させるステップと、
(b)不活性雰囲気中、230℃以上で加熱を行ってFePtあるいはFePd合金ナノ粒子を生成するステップとからなり、
FexM1-x(式中、MはPtまたはPdを表し、xは、MがPtの時、0.40≦x≦0.65であり、MがPdの時、0.49≦x≦0.60である。)で表される組成を有する粒子が全体の60%以上含まれ、かつ平均粒径が2〜10nmの範囲内であるナノ粒子群を製造することを特徴とするナノ粒子群の製造方法。 A method for producing nanoparticles comprising a binary alloy of Fe and Pt or Fe and Pd,
(a) In a nonpolar organic solvent, iron pentacarbonyl and a complex of Pt or Pd are added in the presence of 0.01 to 0.4 mol of an organic protective agent with respect to 1 mol of the Pt or Pd complex. Dissolving in an active atmosphere;
(b) heating at 230 ° C. or higher in an inert atmosphere to generate FePt or FePd alloy nanoparticles,
Fe x M 1-x (wherein M represents Pt or Pd, x is 0.40 ≦ x ≦ 0.65 when M is Pt, and 0.49 ≦ x when M is Pd) ≦ 0.60.) A nanoparticle group comprising 60% or more of particles having a composition represented by the formula (1) and having an average particle diameter in the range of 2 to 10 nm. Production method of particle group.
前記Pdの錯体が、パラジウムトリフェニルホスフィン錯体、パラジウムアンミン錯体、パラジウムエチレンジアミン錯体及びパラジウムアセチルアセトネートからなる群から選ばれる少なくとも一種のパラジウム化合物であることを特徴とする請求項1に記載のナノ粒子群の製造方法。 The Pt complex is at least one platinum compound selected from the group consisting of a platinum ethylenediamine complex, a platinum triethylphosphine complex, a platinum triphenylphosphine complex, a platinum ammine complex, and platinum (II) acetylacetonate,
2. The nanoparticle according to claim 1, wherein the Pd complex is at least one palladium compound selected from the group consisting of a palladium triphenylphosphine complex, a palladium ammine complex, a palladium ethylenediamine complex, and palladium acetylacetonate. Group manufacturing method.
で表される有機化合物の少なくとも一種を含むことを特徴とする請求項1に記載のナノ粒子群の製造方法。 The organic protective agent is a group selected from the group consisting of the formula: R—X (wherein R is a linear or branched hydrocarbon chain containing 5 to 22 carbon atoms, an aromatic hydrocarbon chain and a cyclohexane ring). And X is a group selected from the group consisting of carboxylic acid, phosphonic acid, phosphinic acid, phosphine, sulfonic acid, sulfinic acid and amine.)
The method for producing a group of nanoparticles according to claim 1, comprising at least one organic compound represented by the formula:
FexM1-x(式中、MはPtまたはPdを表し、MがPtの時、0.40≦x≦0.65であり、MがPdの時、0.49≦x≦0.60である。)で表される組成を有する粒子が全体の60%以上含まれ、かつ平均粒径が2〜10nmの範囲内であることを特徴とするナノ粒子群。 A group of nanoparticles comprising a binary alloy of Fe and Pt or Fe and Pd manufactured by the method according to claim 1,
Fe x M 1-x (wherein M represents Pt or Pd, and when M is Pt, 0.40 ≦ x ≦ 0.65, and when M is Pd, 0.49 ≦ x ≦ 0. 60.) A group of nanoparticles, wherein 60% or more of the particles having a composition represented by formula (1) are contained, and the average particle size is in the range of 2 to 10 nm.
The nano particles are nano particles according to claim 5, characterized in that one which expresses an L1 0 ordered phase by heat treatment.
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CN100457340C (en) * | 2006-07-20 | 2009-02-04 | 同济大学 | Prepn process of monodisperse nanometer Fe-Pt alloy particle |
CN115178735A (en) * | 2022-08-18 | 2022-10-14 | 佛山金戈新材料股份有限公司 | AlN @ Fe high-thermal-conductivity wave-absorbing powder and preparation method and application thereof |
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CN100457340C (en) * | 2006-07-20 | 2009-02-04 | 同济大学 | Prepn process of monodisperse nanometer Fe-Pt alloy particle |
JP2008138243A (en) * | 2006-11-30 | 2008-06-19 | Univ Of Tsukuba | METHOD FOR PRODUCING Fe/Pd COMPOSITE NANOPARTICLE |
CN115178735A (en) * | 2022-08-18 | 2022-10-14 | 佛山金戈新材料股份有限公司 | AlN @ Fe high-thermal-conductivity wave-absorbing powder and preparation method and application thereof |
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