JP2007194402A - Magnetic multilayer nanoparticle, its manufacturing method, and magnetic material using the same - Google Patents

Magnetic multilayer nanoparticle, its manufacturing method, and magnetic material using the same Download PDF

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JP2007194402A
JP2007194402A JP2006011089A JP2006011089A JP2007194402A JP 2007194402 A JP2007194402 A JP 2007194402A JP 2006011089 A JP2006011089 A JP 2006011089A JP 2006011089 A JP2006011089 A JP 2006011089A JP 2007194402 A JP2007194402 A JP 2007194402A
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magnetic
nanoparticles
particles
metal
nanoparticle
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Isamu Takeuchi
勇 武内
Takeaki Minamiyama
偉明 南山
Masayoshi Kawahara
正佳 河原
Akira Watanabe
晃 渡邊
Kiyoshi Noshiro
清 野城
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HOSOKAWA FUNTAI GIJUTSU KENKYU
MILLENIUM GATE TECHNOLOGY CO L
MILLENIUM GATE TECHNOLOGY CO Ltd
Hosokawa Powder Technology Research Institute
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HOSOKAWA FUNTAI GIJUTSU KENKYU
MILLENIUM GATE TECHNOLOGY CO L
MILLENIUM GATE TECHNOLOGY CO Ltd
Hosokawa Powder Technology Research Institute
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Abstract

<P>PROBLEM TO BE SOLVED: To provide a magnetic material having a characteristic with high performance and high functions such as the improvement of a magnetic recording density, and to provide magnetic multilayer nanoparticles constituting the material; and to provide its manufacturing method. <P>SOLUTION: The magnetic multilayer nanoparticle is obtained by allowing magnetic particles to have the magnetic characteristic corresponding to usage and purposes by permitting the particle size of the magnetic particle constituting the magnetic material to be a nanosize and coating the surface of the magnetic particle with the thin layer of metal or a metallic oxide having the thickness of several nanometers by an electroless plating method. The magnetic material constituted of the magnetic particles is utilized as the material with high performance and high functions. When a terbium oxide is coated on a YIG particle, for example, a ferromagnetic body and the magnetic multilayer nanoparticle with optical transparency are generated so as to be utilized as a photomagnetic recording medium. The magnetic multilayer nanoparticle coated with excellently conductive zinc oxide is utilized as the magnetic material with an electrostatic absorbent characteristic. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

本発明は、ナノサイズの磁性粒子に金属または金属酸化物をナノサイズの厚さで被覆させた磁性多層ナノ粒子及びその製造方法とそれらで構成される磁性材料に関する。   The present invention relates to a magnetic multilayer nanoparticle in which a metal or metal oxide is coated on a nanosize magnetic particle with a nanosize thickness, a method for producing the same, and a magnetic material composed thereof.

磁性粒子は、磁気テープ等の磁気記録媒体、MO(光磁気ディスク)、ホログラフィック体積記録用材料等の光磁気記録媒体、電波吸収体、電子デバイス等を構成する材料として様々な分野で利用されている。   Magnetic particles are used in various fields as materials constituting magnetic recording media such as magnetic tape, magneto-optical recording media such as MO (magneto-optical disk) and holographic volume recording materials, radio wave absorbers, and electronic devices. ing.

近年、携帯電話、パソコン、デジタルカメラの小型軽量化や画像ファイルの高画質化等に伴い、磁気記録媒体等の磁性材料も高機能化、小型軽量化、大容量化が求められている。これらの要求を満たす方法として、高密度の記録を可能にするため前記磁性材料を構成する磁性粒子を、従来のマイクロサイズからナノサイズへ縮小し、一粒子あたりの磁力や保磁力等の特性を向上させる方法が考えられる。   In recent years, as mobile phones, personal computers, and digital cameras become smaller and lighter and image files have higher image quality, magnetic materials such as magnetic recording media are required to have higher functionality, smaller size, lighter weight, and larger capacity. In order to satisfy these requirements, the magnetic particles constituting the magnetic material are reduced from the conventional micro size to the nano size in order to enable high density recording, and characteristics such as magnetic force and coercive force per particle are obtained. A method of improving it is conceivable.

また、磁性材料の高機能化には、磁性材料の使用用途によって、必要とされる特性が異なるため、使用用途に応じた磁気特性の選択や導電性、光透過性の有無を考慮する必要がある。これらを解決するためには、磁性材料を構成する磁性粒子に必要に応じた磁気特性、導電性、光透過性を持たせればよい。   In addition, since the required properties differ depending on the intended use of the magnetic material in order to increase the functionality of the magnetic material, it is necessary to consider the selection of the magnetic property according to the intended use and the presence or absence of conductivity and light transmission. is there. In order to solve these problems, the magnetic particles constituting the magnetic material may be provided with magnetic properties, conductivity, and light transmittance as required.

一般に、金属磁性粒子は、光透過性を有さず、高い飽和磁束密度と透磁率とを有するが、電気抵抗率が低い。また、金属酸化物磁性粒子は光透過性を有し、金属磁性粒子に比べて電気抵抗率が高いため、磁気特性の劣化は少ないが、飽和磁束密度が金属磁性粒子に比べ低い等、個々の磁性粒子が有する特性は磁性材料としては、一長一短であり、これらを単独で使用する場合、用途に制限が生じる。   In general, metal magnetic particles do not have optical transparency, have high saturation magnetic flux density and magnetic permeability, but have low electrical resistivity. In addition, the metal oxide magnetic particles are light transmissive and have a higher electrical resistivity than the metal magnetic particles, so there is little deterioration in magnetic properties, but the saturation magnetic flux density is lower than that of the metal magnetic particles. The magnetic particles have advantages and disadvantages as a magnetic material. When these materials are used alone, there are limitations on the application.

そこで、これら金属磁性粒子および金属酸化物磁性粒子の両者の長所を有する磁性粒子を提供する方法として、これまで、飽和磁束密度および透磁率が高い金属磁性粒子の表面に、電気抵抗率の高い酸化物磁性材料の被膜を形成した複合磁性多層微粒子等が提案されてきた。(特許文献1参照)   Therefore, as a method of providing magnetic particles having the advantages of both metal magnetic particles and metal oxide magnetic particles, the surface of metal magnetic particles having a high saturation magnetic flux density and high permeability has been oxidized to a high degree. There have been proposed composite magnetic multilayer fine particles and the like formed with a coating of a magnetic material. (See Patent Document 1)

これにより、金属と金属酸化物の特性を併せ持ち、磁気特性を向上させた磁性粒子を生成することが可能となった。しかし、磁性材料を構成する磁性粒子をナノサイズにした場合、比表面積の増大、エネルギー輸送の損失の抑制、量子効果あるいはサイズ効果により、バルク材料と比較して、材料の特性が飛躍的に向上したり、従来予想できなかった固有特性が発現する可能性がある。従って、磁性材料を限界まで小型化、高性能化するためには、ナノスケールでの構造設計を考慮する必要が生じてくる。   As a result, it has become possible to produce magnetic particles having both the characteristics of a metal and a metal oxide and improved magnetic characteristics. However, when the magnetic particles that make up a magnetic material are made nano-sized, the characteristics of the material are dramatically improved compared to bulk materials due to the increase in specific surface area, suppression of energy transport loss, quantum effect or size effect. Or may have inherent characteristics that could not be predicted in the past. Therefore, in order to reduce the size and performance of magnetic materials to the limit, it is necessary to consider nanoscale structural design.

ナノスケールの複合磁性多層微粒子としては、これまで、鉄を主成分として、コバルト及びニッケルを少なくとも含む組成を有する金属粒子に金属酸化物または金属窒化物を被覆したナノサイズ粒子(特許文献2参照)が考えられてきたが、この粒子は、中心となる磁性粒子の主成分が鉄系に限定されており、他の磁性粒子への応用については何ら記載されていなかった。また、その発明の目的は、被覆させる金属または金属酸化物の種類によって選択的に粒子の特性を変化させようとするものではなく、粒子表面の酸化防止や粒子間の凝集防止のために、耐酸化被膜を設けたものだった。また、前記粒子の製造方法は鉄系粒子の粉末と被覆させる金属元素を含有する粉末とを混合して熱処理を施すという単純なものであり、被覆層の厚さが不均一となり易い上、被覆層に不純物が含まれるという問題が生じていた。
特開2004―134795号公報 特開2005―273011号公報
As nano-scale composite magnetic multi-layer fine particles, nano-size particles in which metal particles having a composition containing iron as a main component and containing at least cobalt and nickel are coated with metal oxide or metal nitride (see Patent Document 2). However, in this particle, the main component of the magnetic particle as the center is limited to iron-based, and no application to other magnetic particles has been described. The object of the invention is not to selectively change the characteristics of the particles depending on the type of metal or metal oxide to be coated, but to prevent oxidation of the particle surface and aggregation between particles. A chemical coating was provided. Further, the method for producing the particles is a simple method in which the powder of the iron-based particles and the powder containing the metal element to be coated are mixed and subjected to heat treatment. There was a problem that the layer contained impurities.
JP 2004-134895 A Japanese Patent Laid-Open No. 2005-273011

そこで、本発明は上記問題点に鑑み、使用態様に応じた高機能磁性材料を提供するため、粒径がナノサイズの磁性粒子に用途に応じた特性を持つ金属又は金属酸化物をナノサイズの厚さでめっきした磁性多層ナノ粒子とその製造方法を提供すると共に、前記磁性多層ナノ粒子で構成することで、高性能高機能化した磁性材料を提供することを目的とする。   Therefore, in view of the above-described problems, the present invention provides a high-functional magnetic material according to the use mode, in order to provide a nano-sized metal or metal oxide having characteristics corresponding to the application to a nano-sized magnetic particle. An object of the present invention is to provide a magnetic multilayer nanoparticle plated with a thickness and a method for producing the same, and to provide a magnetic material with high performance and high functionality by being composed of the magnetic multilayer nanoparticle.

上記目的を達成するための本発明の第1の構成は、粒径が1nm以上500nm以下の範囲にある磁性ナノ粒子の表面が、金属または金属酸化物の被膜で覆われている磁性多層ナノ粒子である。   In order to achieve the above object, a first configuration of the present invention is a magnetic multilayer nanoparticle in which the surface of a magnetic nanoparticle having a particle size in the range of 1 nm to 500 nm is covered with a metal or metal oxide film It is.

本発明の第2の構成は、上記第1の構成の磁性多層ナノ粒子において、前記被膜の膜厚が、1nm以上100nm以下の範囲にあることを特徴とする。   According to a second configuration of the present invention, in the magnetic multilayer nanoparticle of the first configuration, the film thickness is in the range of 1 nm to 100 nm.

本発明の第3の構成は、上記第1又は第2の構成の磁性多層ナノ粒子において、前記被膜が、Zn、Fe、Tb、Y、Ceの少なくとも1種の金属の酸化物を含むことを特徴とする。   According to a third configuration of the present invention, in the magnetic multilayer nanoparticles of the first or second configuration, the coating includes an oxide of at least one metal of Zn, Fe, Tb, Y, and Ce. Features.

本発明の第4の構成は、上記第1及至第3のいずれかの構成の磁性多層ナノ粒子において、前記磁性ナノ粒子が、一般式、Ax3-xyFe5-y12(式中、0≦x<3,0≦y<5であり、Aは、Bi、Ca、Ce、Pb、Ptの中から選ばれる1種以上の元素であり、Bは、Yまたは希土類元素の中から選ばれる1種以上の元素であり、Mは、Al、Co、Cr、Cu、Fe(II)、Ga、Ge、Hf、In、Li、Mn、Mo、Nd、
Ni、Pb、Rh、Ru、Sc、Si、Sn、Ti、V、Zn、Zrの中から選ばれる一種以上の元素を示す)で表される磁性体であることを特徴とする。
A fourth embodiment of the present invention is a magnetic multilayer nanoparticles of the first to third any one of the, the magnetic nanoparticles, the general formula, A x B 3-x M y Fe 5-y O 12 (Wherein 0 ≦ x <3, 0 ≦ y <5, A is one or more elements selected from Bi, Ca, Ce, Pb, and Pt, and B is Y or a rare earth element M is one or more elements selected from the group consisting of Al, Co, Cr, Cu, Fe (II), Ga, Ge, Hf, In, Li, Mn, Mo, Nd,
It is a magnetic material represented by at least one element selected from Ni, Pb, Rh, Ru, Sc, Si, Sn, Ti, V, Zn, and Zr.

本発明の第5の構成は、上記第1及至第4のいずれかの構成の磁性多層ナノ粒子で構成される磁性材料である。   According to a fifth aspect of the present invention, there is provided a magnetic material composed of the magnetic multilayer nanoparticles having any one of the first to fourth configurations.

本発明の第6の構成は、粒径が1nm以上500nm以下の範囲にある磁性ナノ粒子を形成するナノ粒子形成工程と、無電解めっき法により、前記磁性ナノ粒子の表面に膜厚が1nm以上100nm以下の金属又は金属酸化物からなる被膜を形成する被膜形成工程と、を含む磁性多層ナノ粒子の製造方法である。   According to a sixth configuration of the present invention, a film thickness of 1 nm or more is formed on the surface of the magnetic nanoparticles by a nanoparticle forming step of forming magnetic nanoparticles having a particle diameter in the range of 1 nm or more and 500 nm or less and an electroless plating method. And a film forming step of forming a film made of a metal or metal oxide of 100 nm or less.

本発明の第1の構成によれば、例えば、磁気記録材料として利用する場合、前記磁性多層ナノ粒子により構成される磁気記録媒体は磁気記録密度が高く、高性能で小型軽量化したものを提供することができる。その他、ナノサイズの磁性粒子の特性を生かした高機能磁性材料を提供することができる。さらに、磁性多層ナノ粒子を磁性材料として加工する際、バインダ等に分散させる工程で前記磁性多層ナノ粒子間の二次凝集を防止し均一な分散体を形成することができる。   According to the first configuration of the present invention, for example, when used as a magnetic recording material, the magnetic recording medium composed of the magnetic multilayer nanoparticles has a high magnetic recording density, a high performance, a small size and a light weight. can do. In addition, it is possible to provide a highly functional magnetic material that takes advantage of the characteristics of nano-sized magnetic particles. Furthermore, when the magnetic multilayer nanoparticles are processed as a magnetic material, secondary aggregation between the magnetic multilayer nanoparticles can be prevented and a uniform dispersion can be formed in a step of dispersing the magnetic multilayer nanoparticles in a binder or the like.

本発明の第2の構成によれば、被膜の膜層が100nm以下と薄いので、磁性多層ナノ粒子の特性を発揮させる上で有利となる。   According to the 2nd structure of this invention, since the film layer of a film is as thin as 100 nm or less, it becomes advantageous when exhibiting the characteristic of a magnetic multilayer nanoparticle.

本発明の第3の構成によれば、被覆させる金属または、金属酸化物の種類により、様々な特性を持つ磁性多層ナノ粒子を提供することができる。例えば、酸化亜鉛を磁性粒子に被膜させた場合、導電性に優れる磁性多層ナノ粒子を提供可能である。また、鉄系磁性粒子に酸化鉄を被膜させた場合、常磁性を有し、不純物を含まない磁性多層ナノ粒子を提供することができる。また、酸化テルビウムは光透過性と常磁性を有し光の偏光面を回転させるファラデー効果が大きいため、光透過性の粒子に被覆させた場合、多機能磁性多層ナノ粒子を提供することができる。酸化イットリウムは赤色発光性を有するので、酸化イットリウムで被覆された磁性多層ナノ粒子は、蛍光材料等として提供することができる。また、酸化セリウムを被覆させた場合、融点が高い酸化セリウム被膜で核となる磁性粒子が被覆され保護されるので、焼結する際、粒子が安定し、粒子間の凝集を防止することができる。   According to the third configuration of the present invention, magnetic multilayer nanoparticles having various characteristics can be provided depending on the type of metal or metal oxide to be coated. For example, when zinc oxide is coated on magnetic particles, magnetic multilayer nanoparticles having excellent conductivity can be provided. Moreover, when iron-based magnetic particles are coated with iron oxide, magnetic multilayer nanoparticles having paramagnetism and containing no impurities can be provided. In addition, terbium oxide has optical transparency and paramagnetism, and has a large Faraday effect of rotating the polarization plane of light. Therefore, when coated with optically transparent particles, multifunctional magnetic multilayer nanoparticles can be provided. . Since yttrium oxide has a red light emitting property, magnetic multilayer nanoparticles coated with yttrium oxide can be provided as a fluorescent material or the like. In addition, when cerium oxide is coated, the magnetic particles serving as the core are covered and protected by a cerium oxide film having a high melting point, so that the particles can be stabilized during sintering and aggregation between the particles can be prevented. .

本発明の第4の構成によれば、磁性ナノ粒子として表記の一般式で表される磁性体の元素組成を選択することにより、種々の特性を持つ磁性多層ナノ粒子が得られる。例えば磁性ナノ粒子にガーネット型磁性体を用いることで、強磁性を有し、且つ光透過性の磁気光学粒子材料として好適な磁性多層ナノ粒子を提供することができる。   According to the fourth configuration of the present invention, magnetic multilayer nanoparticles having various characteristics can be obtained by selecting the elemental composition of the magnetic material represented by the general formula as the magnetic nanoparticles. For example, by using a garnet-type magnetic material for magnetic nanoparticles, magnetic multilayer nanoparticles suitable for a magneto-optical particle material having ferromagnetism and light transmission can be provided.

本発明の第5の構成によれば、記録媒体として使用する場合、磁気記録密度の高い磁気記録媒体を提供することができる。その他、様々な使用目的に沿った高性能磁性材料の提供が可能である。   According to the fifth configuration of the present invention, when used as a recording medium, a magnetic recording medium having a high magnetic recording density can be provided. In addition, it is possible to provide a high-performance magnetic material for various purposes.

本発明の第6の構成によれば、粒径がナノサイズの磁性粒子表面に金属又は金属酸化物の薄膜をナノサイズの厚さで均一に被覆させることが可能であり、めっきする金属または金属酸化物を変えることで異なる特性を持つ磁性多層ナノ粒子を容易に且つ低コストで製造することができる。   According to the sixth configuration of the present invention, it is possible to uniformly coat a metal or metal oxide thin film with a nano-sized thickness on the surface of a magnetic particle having a nano-sized particle diameter. By changing the oxide, magnetic multilayer nanoparticles having different characteristics can be easily produced at low cost.

本発明において用いられる本発明の磁性多層ナノ粒子は、核となる磁性ナノ粒子の表面に、金属または金属酸化物を被膜させたものであり、前記磁性ナノ粒子の粒径は1nm以上500nm以下の範囲であることが好ましい。1nm未満の粒径では、粒子が凝集し易くなり、取り扱いが困難である。また、磁性ナノ粒子の磁気特性が低下してしまい、磁性材料として使用する場合、性能が著しく低下する。粒径が、500nmを超えると粒子を焼結させる場合、低温で焼結することが困難である。また、粒子間の隙間が大きくなり磁気記録密度の低下等、ナノスケールによる構造特性が失われるので好ましくない。   The magnetic multilayer nanoparticle of the present invention used in the present invention is obtained by coating the surface of a magnetic nanoparticle serving as a nucleus with a metal or metal oxide, and the magnetic nanoparticle has a particle size of 1 nm to 500 nm. A range is preferable. When the particle diameter is less than 1 nm, the particles are likely to aggregate and are difficult to handle. In addition, the magnetic properties of the magnetic nanoparticles are degraded, and the performance is significantly degraded when used as a magnetic material. When the particle size exceeds 500 nm, it is difficult to sinter at low temperatures when the particles are sintered. Further, it is not preferable because the gap between the particles becomes large and structural properties on the nanoscale such as a decrease in magnetic recording density are lost.

前記金属又は金属酸化物被膜の膜厚は、1nm以上100nm以下の範囲であることが好ましい。1nm未満の膜厚では、製造技術上、均一の膜を形成することが難しく、100nmを超えると、磁性多層ナノ粒子の特性を発揮させる上で不利となるからである。   The thickness of the metal or metal oxide film is preferably in the range of 1 nm to 100 nm. If the film thickness is less than 1 nm, it is difficult to form a uniform film in terms of manufacturing technology, and if it exceeds 100 nm, it is disadvantageous for exhibiting the characteristics of the magnetic multilayer nanoparticles.

本発明に用いられる核となる磁性ナノ粒子としては、鉄やコバルト、バーマロイ等で形成された種々の磁性粒子を用いることが可能であるが、磁性ナノ粒子として、一般式、Ax3-xyFe5-y12(式中、0≦x<3,0≦y<5であり、Aは、Bi、Ca、Ce、Pb、Ptの中から選ばれる1種以上の元素であり、Bは、Y(イットリウム)または希土類元素の中から選ばれる1種以上の元素、具体的にはCe、Dy、Eu、Er、Gd、Ho、La、Lu、Nd、Pm、Pr、Sm、Tb、Tm、Y、Ybなどであり、Mは、Al、Co、Cr、Cu、Fe(II)、Ga、Ge、Hf、In、Li、Mn、Mo、Nd、Ni、Pb、Rh、Ru、Sc、Si、Sn、Ti、V、Zn、Zrの中から選ばれる一種以上の元素を示す。)で表される磁性体、例えばガーネット型磁性体が好ましい。ここでx=0,BがY(イットリウム)で、y=0のとき、代表的な酸化物磁性体である組成式Y3Fe512で表されるイットリウム−鉄ガーネット(Yttrium Iron Garnet、以下YIGと称す)となる。また、この組成の中で、Yの一部をBi、Gdなどで置換し、Feの一部をGa、In、Alなどで置換することができる。このように置換したYIGを置換型YIGといい、置換型YIGを用いた場合、キュリー温度、磁気異方性、磁気ひずみ係数等を変化させることができる。 Various magnetic particles formed of iron, cobalt, vermalloy, or the like can be used as the magnetic nanoparticle serving as a nucleus used in the present invention. As the magnetic nanoparticle, a general formula, A x B 3− during x M y Fe 5-y O 12 ( where a 0 ≦ x <3,0 ≦ y < 5, a is, Bi, Ca, Ce, Pb, at least one element selected from among Pt B is one or more elements selected from Y (yttrium) or rare earth elements, specifically, Ce, Dy, Eu, Er, Gd, Ho, La, Lu, Nd, Pm, Pr, Sm , Tb, Tm, Y, Yb, etc., and M is Al, Co, Cr, Cu, Fe (II), Ga, Ge, Hf, In, Li, Mn, Mo, Nd, Ni, Pb, Rh, One or more elements selected from Ru, Sc, Si, Sn, Ti, V, Zn, and Zr are shown. ), For example, a garnet type magnetic body is preferable. Here, when x = 0, B is Y (yttrium), and y = 0, yttrium-iron garnet (Yttrium Iron Garnet) represented by the composition formula Y 3 Fe 5 O 12 , which is a typical oxide magnetic material, Hereinafter referred to as YIG). Further, in this composition, a part of Y can be substituted with Bi, Gd, and the like, and a part of Fe can be substituted with Ga, In, Al, and the like. The YIG thus substituted is called a substitution type YIG, and when the substitution type YIG is used, the Curie temperature, the magnetic anisotropy, the magnetostriction coefficient, etc. can be changed.

本発明の磁性多層ナノ粒子は、磁性材料の形成に用いることができる。磁性材料の使用態様としては、磁気テープ、磁気記録ディスク、ハードディスク、等の磁気記録媒体やMO(光磁気ディスク)、ホログラフィック体積記録用材料等の光磁気記録媒体、電波吸収体、インダクタ、プリント基板等の電子デバイス、生体物質抽出用の磁気ビーズ等が挙げられる。例えば磁気記録媒体を高性能化し記録容量の向上を図る場合、磁化点移転のノイズや、反磁界を低減させるため、磁性粒子の粒径を小さくして、磁気記録密度を向上させるとともに、保磁力と飽和磁化量の大きい磁性粒子を材料とする必要がある。また光磁気記録媒体を高性能化する場合、光透過性が上記特性に加えて必要になるので、磁性多層ナノ粒子はYIG粒子のような光透過性を有する磁性粒子に透過性を有さない金属ではなく、光透過性を有する金属酸化物を被覆する必要がある。   The magnetic multilayer nanoparticles of the present invention can be used to form a magnetic material. Magnetic materials can be used in magnetic recording media such as magnetic tapes, magnetic recording disks, and hard disks, magneto-optical recording media such as MO (magneto-optical disks) and holographic volume recording materials, radio wave absorbers, inductors, and prints. Examples thereof include electronic devices such as substrates, magnetic beads for extracting biological substances, and the like. For example, when improving the recording capacity by improving the performance of a magnetic recording medium, the magnetic recording density is improved by reducing the particle size of the magnetic particles in order to reduce the magnetization point transfer noise and the demagnetizing field. It is necessary to use magnetic particles having a large saturation magnetization as a material. In addition, in order to improve the performance of magneto-optical recording media, optical transparency is required in addition to the above characteristics. Therefore, magnetic multilayer nanoparticles do not have permeability to magnetic particles having optical transparency such as YIG particles. It is necessary to coat a metal oxide having optical transparency instead of a metal.

また、磁性多層ナノ粒子を電子デバイス表面に塗布し電波吸収体として使用する場合、強磁性と強誘電性を有する磁性多層ナノ粒子を材料とする必要があり、例えば、中心核の磁性粒子に誘電率の高い粒子を用い、無電解めっきで金属コバルト金属ニッケルの層を被覆した上にフェライトめっき等の磁性の強い被覆を設ける必要がある。   In addition, when magnetic multilayer nanoparticles are applied to the surface of an electronic device and used as a radio wave absorber, it is necessary to use magnetic multilayer nanoparticles having ferromagnetism and ferroelectricity as a material. It is necessary to provide a highly magnetic coating such as ferrite plating on the metal cobalt metal nickel layer by electroless plating using particles having a high rate.

また、導電性を有する酸化亜鉛を被覆した磁性多層ナノ粒子を電子デバイスに塗布した場合、静電気吸収効果が働き、超小型回路等を静電気から保護することができる。   In addition, when magnetic multilayer nanoparticles coated with conductive zinc oxide are applied to an electronic device, an electrostatic absorption effect works, and a microcircuit or the like can be protected from static electricity.

本発明の磁性多層ナノ粒子の製造に用いられる磁性ナノ粒子は、気相反応法や燃焼噴霧法等の製造方法を用いて製造することができる(ナノ粒子形成工程)。気相反応法による磁性ナノ粒子の製造方法について概要を説明すると、反応後の磁性ナノ粒子が所定の組成比となるように、磁性ナノ粒子を構成する各金属成分を含む原料液を調製する。次に、反応気体(酸素ガス)と共に噴霧ノズルを使用して、例えば高温プラズマにより発生させた高温雰囲気(約3,000℃)の反応空間に原料液を噴霧し、反応気体流で覆われた原料液の液滴流を生成するとともに、液滴の蒸発気化による粒子核形成と粒子成長を行わせた後、周囲の冷却ガスで急速冷却して所定サイズの磁性ナノ粒子を製造する。   The magnetic nanoparticles used in the production of the magnetic multilayer nanoparticles of the present invention can be produced using a production method such as a gas phase reaction method or a combustion spray method (nanoparticle formation step). The outline of the method for producing magnetic nanoparticles by the gas phase reaction method will be described. A raw material liquid containing each metal component constituting the magnetic nanoparticles is prepared so that the magnetic nanoparticles after the reaction have a predetermined composition ratio. Next, using a spray nozzle together with the reaction gas (oxygen gas), for example, the raw material liquid was sprayed into the reaction space of a high-temperature atmosphere (about 3,000 ° C.) generated by high-temperature plasma and covered with the reaction gas flow. A droplet flow of the raw material liquid is generated and particle nucleation and particle growth are performed by evaporation of droplets, and then rapidly cooled with a surrounding cooling gas to produce magnetic nanoparticles of a predetermined size.

原料液は、例えばYIG粒子のYの一部をBiで置換した組成式Bi0.52.5Fe512で表される置換型YIG粒子を製造する場合、2−エチルヘキサン酸イットリウム、2−エチルヘキサン酸ビスマス、2−エチルヘキサン酸第二鉄の各有機化合物を所定モル比になるように調合、混合したものを石油系炭化水素(ミネラルスピリット等)中に溶解して調製される。 The raw material liquid is, for example, yttrium 2-ethylhexanoate, 2-ethyl when producing substituted YIG particles represented by the composition formula Bi 0.5 Y 2.5 Fe 5 O 12 in which Y is partially substituted with Bi. Prepared by dissolving and mixing the organic compounds of bismuth hexanoate and ferric 2-ethylhexanoate in a predetermined molar ratio in petroleum hydrocarbons (mineral spirits, etc.).

また、このようにして製造された磁性ナノ粒子の平均粒子径は粒子単位重量当りの表面積(BET値)を実測し、BET値から下記式(1)を用いてBET換算径を計算することにより求められる。
BET換算径(nm)=6/BET値(m2/g)/真密度(g/cm3)×1000
‥‥(1)
Further, the average particle diameter of the magnetic nanoparticles thus produced is obtained by actually measuring the surface area per unit weight (BET value) and calculating the BET equivalent diameter from the BET value using the following formula (1). Desired.
BET equivalent diameter (nm) = 6 / BET value (m 2 / g) / true density (g / cm 3 ) × 1000
(1)

次に、このようにして形成された磁性ナノ粒子の表面に、無電解めっき法により金属又は金属酸化物からなる被膜を形成する(被膜形成工程)。無電解めっき法を用いるのは、通常の電気めっき法では、ナノサイズの粒子をめっきすることは難しく、均一の厚さにめっきすることができないためである。   Next, a film made of a metal or a metal oxide is formed on the surface of the magnetic nanoparticles thus formed by an electroless plating method (film formation process). The reason why the electroless plating method is used is that it is difficult to plate nano-sized particles in a normal electroplating method, and it is impossible to plate to a uniform thickness.

無電解めっき法は、一般的に触媒化処理工程と無電解めっき工程を少なくとも含む工程により構成されている。触媒化処理工程は一般的にキャタリスト(キャタライジング)―アクセレータ(アクセレーティング)法とセンシタイジング―アクチベーティング法があり、どちらを用いても良い。   The electroless plating method is generally configured by a process including at least a catalytic treatment process and an electroless plating process. The catalyst treatment process generally includes a catalyst (catalyzing) -accelerator (accelrating) method and a sensitizing-activating method, either of which may be used.

キャタリスト(キャタライジング)―アクセレータ(アクセレーティング)法とは、塩化スズ、塩化パラジウム、塩酸の混合溶液(キャタリスト)に磁性粒子を浸漬して、表面にパラジウム・スズ錯体化合物などを吸着させた後、前記磁性粒子をアクセレータ(硫酸、塩酸などの酸溶液または水酸化ナトリウム、アンモニアなどのアルカリ溶液)に浸漬させ、スズを除去しパラジウムを活性化するものである。   The catalyst (catalyzing) -accelerator (acceleration) method is a method in which magnetic particles are immersed in a mixed solution (catalyst) of tin chloride, palladium chloride, and hydrochloric acid to adsorb palladium-tin complex compounds on the surface. Thereafter, the magnetic particles are immersed in an accelerator (an acid solution such as sulfuric acid or hydrochloric acid or an alkali solution such as sodium hydroxide or ammonia) to remove tin and activate palladium.

センシタイジング―アクチベーティング法とは、還元力の強い塩化スズ溶液(センシタイジング)に磁性粒子を浸漬し、前記磁性粒子表面にスズを吸着させた後、塩化パラジウム溶液(アクチベーティング)に浸漬し、触媒能のあるパラジウムなどの触媒層を磁性粒子表面に担持させる方法である。   Sensitizing-activating method is a method of immersing magnetic particles in tin chloride solution (sensitizing) with strong reducing power, adsorbing tin on the surface of the magnetic particles, and then palladium chloride solution (activating). In this method, a catalyst layer such as palladium having catalytic ability is supported on the surface of magnetic particles.

無電解めっき工程とは、パラジウムなどの触媒層が担持された表面上に金属または金属酸化物の薄膜を形成させるための工程である。この工程では、上記工程により処理された磁性粒子を無電解めっき溶液に浸漬すると、めっき液中の還元剤が触媒活性なパラジウム表面で酸化される。この放出される電子によって溶液中の金属イオンまたは金属酸化物イオンが還元され、パラジウムの触媒核付近から金属の析出が始まりめっき被膜を生成する。   The electroless plating process is a process for forming a metal or metal oxide thin film on the surface on which a catalyst layer such as palladium is supported. In this step, when the magnetic particles treated in the above step are immersed in an electroless plating solution, the reducing agent in the plating solution is oxidized on the catalytically active palladium surface. Metal ions or metal oxide ions in the solution are reduced by the emitted electrons, and metal deposition starts from the vicinity of the catalytic nucleus of palladium to form a plating film.

無電解めっきに用いられる金属の種類としては、Al、Si、Sc、Ti、V、Cr、Mn、Fe、Co、Ni、Cu、Zn、Ga、Ge、Y、Zr、Nb、Mo、Ru、Rh、Rd、Ag、Cd、In、Sn、La、Ce、Pr、Nd、Sm、Eu,Gd、Tb、Dy、Ho、Er、Tm、Yb、Lu、W、Pt、Au、Tl、Pb、Biのうち少なくとも1種を含むものであれば良く、めっきは金属又は金属酸化物でもかまわない。   The types of metals used for electroless plating include Al, Si, Sc, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Ga, Ge, Y, Zr, Nb, Mo, Ru, Rh, Rd, Ag, Cd, In, Sn, La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu, W, Pt, Au, Tl, Pb, As long as it contains at least one of Bi, the plating may be a metal or a metal oxide.

金属は一般的に、光透過性はないが、金属酸化物は、光透過性を有するものがある。例えば、光透過性に優れるYIG粒子に酸化テルビウムを被膜させた磁性多層ナノ粒子は、強磁性体であり、光透過性を有するため、MO(光磁気ディスク)、ホログラフィック体積記録用材料等の光磁気記録媒体としての利用が見込まれる。   Metals are generally not light transmissive, but some metal oxides are light transmissive. For example, magnetic multilayer nanoparticles in which YIG particles having excellent light transmittance are coated with terbium oxide are ferromagnetic and have light transmittance. Therefore, MO (magneto-optical disks), holographic volume recording materials, etc. Use as a magneto-optical recording medium is expected.

また、上記金属の中でも、特にZn、Fe、Tb、Y、Ceの少なくとも1種の金属の酸化物で被膜を形成することが好ましい。酸化亜鉛は導電性に優れるため、酸化亜鉛を被覆した磁性多層ナノ粒子は静電気吸収特性を有する磁性材料として利用可能であり、また、この導電性を利用すると、磁性多層ナノ粒子を担体に電気的に付着させて磁気材料を形成する場合に好適である。その他にも、酸化セリウムは融点が高いため、酸化セリウムで被覆された磁性多層ナノ粒子を形成した後に内部の磁性ナノ粒子を結晶化する際、焼結工程で表面の酸化セリウムが核となる磁性粒子の熱融着による粒子間の凝集を防ぎ、均一な結晶構造を作ることができる。また、YIG粒子等の鉄系磁性粒子に酸化鉄或いは酸化イットリウムを被覆させる場合、核となる磁性ナノ粒子及び被膜の両方に鉄またはイットリウムを含有した、常磁性を有し、不純物を含まない磁性多層ナノ粒子を提供することができる。例えば磁性記録材料とした場合に記録容量を増大させることができる。   Moreover, it is preferable to form a film with the oxide of at least 1 sort (s) of metal especially Zn, Fe, Tb, Y, and Ce among the said metals. Since zinc oxide is excellent in electrical conductivity, magnetic multilayer nanoparticles coated with zinc oxide can be used as a magnetic material having electrostatic absorption characteristics. By using this electrical conductivity, magnetic multilayer nanoparticles can be electrically used as a carrier. It is suitable when it is made to adhere to and forms a magnetic material. In addition, since cerium oxide has a high melting point, when crystallization of internal magnetic nanoparticles after formation of magnetic multilayer nanoparticles coated with cerium oxide, the magnetic properties of which the surface cerium oxide becomes the nucleus during the sintering process Aggregation between particles due to heat fusion of the particles can be prevented, and a uniform crystal structure can be formed. In addition, when iron-based magnetic particles such as YIG particles are coated with iron oxide or yttrium oxide, both the core magnetic nanoparticle and the coating contain iron or yttrium and have paramagnetism and no impurities. Multi-layer nanoparticles can be provided. For example, when a magnetic recording material is used, the recording capacity can be increased.

さらに、本発明の磁性多層ナノ粒子を粉末冶金の原料として用いることもできる。その場合、核となる磁性ナノ粒子と被膜とが異なる金属で形成された磁性多層ナノ粒子を用いることにより、磁性多層ナノ粒子を金型に充填して焼結させる際に、粒子内部の金属と被膜を構成する金属とを反応させて、種々の合金から成る部品を簡便に製造することができる。   Furthermore, the magnetic multilayer nanoparticles of the present invention can also be used as a raw material for powder metallurgy. In that case, by using magnetic multilayer nanoparticles formed of a metal whose core and magnetic nanoparticles are different from each other, when the magnetic multilayer nanoparticles are filled in a mold and sintered, the metal inside the particles Parts made of various alloys can be easily manufactured by reacting with the metal constituting the coating.

無電解めっきに用いられる金属源としては、Al、Si、Sc、Ti、V、Cr、Mn、Fe、Co、Ni、Cu、Zn、Ga、Ge、Y、Zr、Nb、Mo、Ru、Rh、Rd、Ag、Cd、In、Sn、La、Ce、Pr、Nd、Sm、Eu,Gd、Tb、Dy、Ho、Er、Tm、Yb、Lu、W、Pt、Au、Tl、Pb、Biのいずれかを含む水溶性金属塩を使用する。水溶性塩として、硝酸塩、亜硝酸塩、硫酸塩、シュウ酸塩、炭酸塩、塩化物、酢酸塩、乳酸塩、スルファミン酸塩、フッ化物、ヨウ化物、シアン化物等などが用いられる。   As a metal source used for electroless plating, Al, Si, Sc, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Ga, Ge, Y, Zr, Nb, Mo, Ru, Rh , Rd, Ag, Cd, In, Sn, La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu, W, Pt, Au, Tl, Pb, Bi A water-soluble metal salt containing any of the above is used. As the water-soluble salt, nitrate, nitrite, sulfate, oxalate, carbonate, chloride, acetate, lactate, sulfamate, fluoride, iodide, cyanide and the like are used.

本発明で使用する還元剤としては、次亜リン酸、ホルムアルデヒド、水素化ボロン、ジメチルアミンボラン、トリメチルアミンボラン、ヒドラジンなどが用いられる。   As the reducing agent used in the present invention, hypophosphorous acid, formaldehyde, boron hydride, dimethylamine borane, trimethylamine borane, hydrazine and the like are used.

また、無電解めっき工程において、前記無電解めっき溶液には錯化剤を添加する。本発明で使用する錯化剤としては、コハク酸などのジカルボン酸、クエン酸、酒石酸などのオキシカルボン酸、グリシン、EDTA、アミノ酢酸などの有機酸、またはこれらのナトリウム塩などが用いられる。これらの錯化剤を用いることで、安定して金属または金属酸化物の被膜を形成することが可能となる。   In the electroless plating step, a complexing agent is added to the electroless plating solution. As the complexing agent used in the present invention, dicarboxylic acids such as succinic acid, oxycarboxylic acids such as citric acid and tartaric acid, organic acids such as glycine, EDTA and aminoacetic acid, or sodium salts thereof are used. By using these complexing agents, it is possible to stably form a metal or metal oxide film.

次に、本発明を実施例に基づいて具体的に説明する。しかし、本発明は上述した実施形態及び後述する各実施例に限定されるものではなく、課題を解決するための手段の項に示した範囲で種々の変更が可能であり、異なる実施形態及び実施例にそれぞれ開示された技術的手段を適宜組み合わせて得られる実施形態についても本発明の技術的範囲に含まれる。
[磁性ナノ粒子の製造]
Next, the present invention will be specifically described based on examples. However, the present invention is not limited to the above-described embodiment and each example to be described later, and various modifications are possible within the scope shown in the section of means for solving the problem, and different embodiments and implementations are possible. Embodiments obtained by appropriately combining the technical means disclosed in the examples are also included in the technical scope of the present invention.
[Production of magnetic nanoparticles]

原料として、2−エチルヘキサン酸イットリウム、2−エチルヘキサン酸ビスマス、及び2−エチルヘキサン酸第二鉄をミネラルスピリットにBi:Y:Fe=0.5:2.5:5のモル比となるように混合して原料液を調製した。次に、この原料液を酸素ガスと共に噴霧ノズルを用いて高温プラズマにより発生させた約3000℃の反応空間に噴霧し、酸素ガスで覆われた液滴流を生成するとともに、液滴の蒸発気化による粒子核形成と粒子成長を行わせた後、周囲の冷却ガスで急速冷却して、組成式Bi0.52.5Fe512粒子で表される置換型YIG粒子を得た。 As raw materials, yttrium 2-ethylhexanoate, bismuth 2-ethylhexanoate, and ferric 2-ethylhexanoate are used as mineral spirits, and the molar ratio is Bi: Y: Fe = 0.5: 2.5: 5. The raw material liquid was prepared by mixing as described above. Next, this raw material liquid is sprayed together with oxygen gas into a reaction space of about 3000 ° C. generated by high-temperature plasma using a spray nozzle to generate a droplet flow covered with oxygen gas and evaporate the droplets. After carrying out particle nucleation and particle growth by the above, rapid cooling with ambient cooling gas was performed to obtain substitutional YIG particles represented by composition formula Bi 0.5 Y 2.5 Fe 5 O 12 particles.

粒子を電子顕微鏡(JEOL製)で観察したところ、図1に示されるように、粒径が約20nmから約100nmの粒子が複数、観察された。また、得られた粒子についてBET値を実測すると23m2/gであり、BET換算径を計算すると45nmであった。尚、Bi0.52.5Fe512の真密度は5.72g/cm3とした。
[金属酸化物被覆磁性ナノ粒子の製造]
When the particles were observed with an electron microscope (manufactured by JEOL), a plurality of particles having a particle size of about 20 nm to about 100 nm were observed as shown in FIG. Further, when the BET value of the obtained particles was measured, it was 23 m 2 / g, and the calculated BET diameter was 45 nm. The true density of Bi 0.5 Y 2.5 Fe 5 O 12 was 5.72 g / cm 3 .
[Production of metal oxide-coated magnetic nanoparticles]

実施例1で得られた置換型YIG粒子(Bi0.52.5Fe512)を分散処理し、その2gを塩化錫(和光純薬製)3g/L、塩酸1ml/Lの水溶液1Lに浸漬させ、5分間攪拌処理し、固液分離後、塩化パラジウム(和光純薬製)1g/L、塩酸1ml/Lの水溶液1Lに浸漬させ、5分間攪拌処理してパラジウムを担持させた。その後、再び固液分離し、硝酸亜鉛(和光純薬製)2g/L、ジメチルアミンボラン(DMAB、和光純薬製)1g/Lの溶液2Lに浸漬させ50℃、2時間攪拌処理し固液分離すると酸化亜鉛によりめっき被膜された磁性多層ナノ粒子2.4gが得られた。 The substituted YIG particles (Bi 0.5 Y 2.5 Fe 5 O 12 ) obtained in Example 1 were dispersed, and 2 g of the particles were immersed in 1 L of an aqueous solution of 3 g / L tin chloride (manufactured by Wako Pure Chemical Industries) and 1 ml / L hydrochloric acid. The mixture was stirred for 5 minutes, and after solid-liquid separation, it was immersed in 1 L of an aqueous solution of palladium chloride (manufactured by Wako Pure Chemical Industries) 1 g / L and hydrochloric acid 1 ml / L, and stirred for 5 minutes to carry palladium. Thereafter, the solid-liquid separation is performed again, and the mixture is immersed in 2 L of a solution of zinc nitrate (made by Wako Pure Chemical Industries) 2 g / L and dimethylamine borane (DMAB, manufactured by Wako Pure Chemical Industries) 1 g / L. When separated, 2.4 g of magnetic multilayer nanoparticles plated with zinc oxide were obtained.

得られた磁性多層ナノ粒子を、電子顕微鏡(JEOL製)で観察したところ、図2、図3に示されるように、粒径が約20nmの磁性粒子に酸化亜鉛が厚さ約3nmで均一に被覆された磁性多層ナノ粒子が観察された。   When the obtained magnetic multilayer nanoparticles were observed with an electron microscope (manufactured by JEOL), as shown in FIG. 2 and FIG. 3, the magnetic particles having a particle diameter of about 20 nm were uniformly formed with zinc oxide having a thickness of about 3 nm. Coated magnetic multilayer nanoparticles were observed.

実施例1で得られた置換型YIG粒子(Bi0.52.5Fe512)を分散処理し、その2gを塩化パラジウム(和光純薬製)0.1g/L、塩化錫(和光純薬製)10g/L、塩酸150ml/Lの水溶液1Lに浸漬させ、5分間攪拌処理し、固液分離後、硫酸50ml/Lの水溶液1Lに浸漬させ、5分間攪拌処理してパラジウムを担持させた。その後、再び固液分離し、硝酸テルビウム(和光純薬製)4g/L、トリメチルアミンボラン(TMAB、和光純薬製)2g/Lの溶液1Lに浸漬させ40℃、2時間攪拌処理し固液分離すると酸化テルビウムによりめっき被膜された磁性多層ナノ粒子2.8gが得られた。また、得られた磁性多層ナノ粒子を蛍光X線分析により解析したところ、図4に示すようにテルビウムのピークが観察され、粒子表面に酸化テルビウムが被覆されていることが確認された。なお、図4の分析により得られた、酸化テルビウムでめっき被膜した磁性多層ナノ粒子の元素の質量濃度比を表1に示す。 The substituted YIG particles (Bi 0.5 Y 2.5 Fe 5 O 12 ) obtained in Example 1 were dispersed, 2 g of palladium chloride (manufactured by Wako Pure Chemical Industries, Ltd.) 0.1 g / L, tin chloride (manufactured by Wako Pure Chemical Industries, Ltd.) ) It was immersed in 1 L of an aqueous solution of 10 g / L and hydrochloric acid 150 ml / L and stirred for 5 minutes. After solid-liquid separation, it was immersed in 1 L of an aqueous solution of 50 ml / L sulfuric acid and stirred for 5 minutes to carry palladium. Thereafter, the solid-liquid separation is performed again, and the resultant is immersed in 1 L of a solution of 4 g / L terbium nitrate (manufactured by Wako Pure Chemical Industries, Ltd.) and 2 g / L of trimethylamine borane (TMAB, manufactured by Wako Pure Chemical Industries, Ltd.). As a result, 2.8 g of magnetic multilayer nanoparticles plated with terbium oxide were obtained. When the obtained magnetic multilayer nanoparticles were analyzed by fluorescent X-ray analysis, a terbium peak was observed as shown in FIG. 4, and it was confirmed that the particle surface was coated with terbium oxide. In addition, Table 1 shows the mass concentration ratio of elements of the magnetic multilayer nanoparticles plated with terbium oxide obtained by the analysis of FIG.

実施例1で得られた置換型YIG粒子(Bi0.52.5Fe512)を分散処理し、その2gを塩化錫(和光純薬製)5g/L、塩酸1ml/Lの水溶液1Lに浸漬させ、5分間攪拌処理し、固液分離後、塩化パラジウム(和光純薬製)0.5g/L、塩酸0.1ml/Lの水溶液1Lに浸漬させ、5分間攪拌処理してパラジウムを担持させた。その後、再び固液分離し、硝酸テルビウム(和光純薬製)4g/L、ジメチルアミンボラン(DMAB、和光純薬製)1g/Lの溶液1Lに浸漬させ50℃、2時間攪拌処理し固液分離すると酸化テルビウムによりめっき被膜された磁性多層ナノ粒子2.7gが得られた。 The substituted YIG particles (Bi 0.5 Y 2.5 Fe 5 O 12 ) obtained in Example 1 were dispersed, and 2 g thereof was immersed in 1 L of an aqueous solution of 5 g / L tin chloride (manufactured by Wako Pure Chemical Industries) and 1 ml / L hydrochloric acid. The mixture is stirred for 5 minutes, and after solid-liquid separation, it is immersed in 1 L of an aqueous solution of palladium chloride (manufactured by Wako Pure Chemical Industries) 0.5 g / L and hydrochloric acid 0.1 ml / L, and stirred for 5 minutes to carry palladium. It was. Then, it was separated into solid and liquid again, immersed in 1 L of a solution of 4 g / L terbium nitrate (manufactured by Wako Pure Chemical Industries) and 1 g / L of dimethylamine borane (DMAB, manufactured by Wako Pure Chemical Industries), stirred at 50 ° C. for 2 hours, and solid-liquid. When separated, 2.7 g of magnetic multilayer nanoparticles plated with terbium oxide were obtained.

実施例1で得られた置換型YIG粒子(Bi0.52.5Fe512)を分散処理し、その2gを塩化パラジウム(和光純薬製)0.1g/L、塩化錫(和光純薬製)20g/L、塩酸130ml/Lの水溶液1Lに浸漬させ、5分間攪拌処理し、固液分離後、硫酸30ml/Lの水溶液1Lに浸漬させ、5分間攪拌処理してパラジウムを担持させた。その後、再び固液分離し、硝酸セリウム(和光純薬製)3g/L、トリメチルアミンボラン(TMAB、和光純薬製)1g/Lの溶液1Lに浸漬させ60℃、2時間攪拌処理し固液分離すると酸化セリウムによりめっき被膜された磁性多層ナノ粒子2.6gが得られた。
[金属被覆磁性ナノ粒子の製造]
The substituted YIG particles (Bi 0.5 Y 2.5 Fe 5 O 12 ) obtained in Example 1 were dispersed, 2 g of palladium chloride (manufactured by Wako Pure Chemical Industries, Ltd.) 0.1 g / L, tin chloride (manufactured by Wako Pure Chemical Industries, Ltd.) ) It was immersed in 1 L of an aqueous solution of 20 g / L and hydrochloric acid 130 ml / L and stirred for 5 minutes. After solid-liquid separation, it was immersed in 1 L of an aqueous solution of 30 ml / L sulfuric acid and stirred for 5 minutes to carry palladium. Thereafter, the solid-liquid separation is performed again, and the resultant is immersed in 1 L of a solution of cerium nitrate (manufactured by Wako Pure Chemical Industries) 3 g / L and trimethylamine borane (TMAB, manufactured by Wako Pure Chemical Industries) 1 g / L. As a result, 2.6 g of magnetic multilayer nanoparticles plated with cerium oxide were obtained.
[Production of metal-coated magnetic nanoparticles]

実施例1で得られた置換型YIG粒子(Bi0.52.5Fe512)を分散処理し、その2gを塩化錫(和光純薬製)5g/L、塩酸1ml/Lの水溶液1Lに浸漬させ、5分間攪拌処理し、固液分離後、塩化パラジウム(和光純薬製)0.5g/L、塩酸0.1ml/Lの水溶液1Lに浸漬させ、5分間攪拌処理してパラジウムを担持させた。その後、再び固液分離し、硫酸ニッケル(和光純薬製)20g/L、次亜リン酸ナトリウム(和光純薬製)25g/L、クエン酸(和光純薬製)30g/Lを含む溶液1Lに浸漬させ80℃、1時間攪拌処理し固液分離するとNi−P合金によりめっき被膜された磁性多層ナノ粒子2.7gが得られた。 The substituted YIG particles (Bi 0.5 Y 2.5 Fe 5 O 12 ) obtained in Example 1 were dispersed, and 2 g thereof was immersed in 1 L of an aqueous solution of 5 g / L tin chloride (manufactured by Wako Pure Chemical Industries) and 1 ml / L hydrochloric acid. The mixture is stirred for 5 minutes, and after solid-liquid separation, it is immersed in 1 L of an aqueous solution of palladium chloride (manufactured by Wako Pure Chemical Industries) 0.5 g / L and hydrochloric acid 0.1 ml / L, and stirred for 5 minutes to carry palladium. It was. Thereafter, solid-liquid separation is performed again, and 1 L of a solution containing nickel sulfate (manufactured by Wako Pure Chemical Industries) 20 g / L, sodium hypophosphite (manufactured by Wako Pure Chemical Industries) 25 g / L, and citric acid (manufactured by Wako Pure Chemical Industries) 30 g / L When this was immersed in the solution and stirred at 80 ° C. for 1 hour to separate into solid and liquid, 2.7 g of magnetic multilayer nanoparticles coated with a Ni—P alloy was obtained.

実施例1で得られた置換型YIG粒子(Bi0.52.5Fe512)を分散処理し、その2gを塩化パラジウム(和光純薬製)0.1g/L、塩化錫(和光純薬製)10g/L、塩酸150ml/Lの水溶液1Lに浸漬させ、5分間攪拌処理し、固液分離後、硫酸50ml/Lの水溶液1Lに浸漬させ、5分間攪拌処理してパラジウムを担持させた。その後、再び固液分離し、硝酸銀(和光純薬製)5g/L、ホルマリン(和光純薬製)2g/L、エチレンジアミン(和光純薬製)10g/Lの溶液0.5Lに浸漬させ30℃、1時間攪拌処理し固液分離すると銀によりめっき被膜された磁性多層ナノ粒子2.2gが得られた。 The substituted YIG particles (Bi 0.5 Y 2.5 Fe 5 O 12 ) obtained in Example 1 were dispersed, 2 g of palladium chloride (manufactured by Wako Pure Chemical Industries, Ltd.) 0.1 g / L, tin chloride (manufactured by Wako Pure Chemical Industries, Ltd.) ) It was immersed in 1 L of an aqueous solution of 10 g / L and hydrochloric acid 150 ml / L and stirred for 5 minutes. After solid-liquid separation, it was immersed in 1 L of an aqueous solution of 50 ml / L sulfuric acid and stirred for 5 minutes to carry palladium. Then, it is again solid-liquid separated and immersed in 0.5 L of a solution of silver nitrate (manufactured by Wako Pure Chemical Industries) 5 g / L, formalin (manufactured by Wako Pure Chemical Industries) 2 g / L, ethylenediamine (manufactured by Wako Pure Chemical Industries) 10 g / L, and 30 ° C. After stirring for 1 hour and solid-liquid separation, 2.2 g of magnetic multilayer nanoparticles coated with silver were obtained.

得られた磁性多層ナノ粒子を蛍光X線分析により解析したところ、図5に示すように銀のピークが観察され、粒子表面に銀が被覆されていることが確認された。なお、図5の分析により得られた、銀でめっき被膜した磁性多層ナノ粒子の元素の質量濃度比を表2に示す。   When the obtained magnetic multilayer nanoparticles were analyzed by fluorescent X-ray analysis, a silver peak was observed as shown in FIG. 5, and it was confirmed that the particle surface was coated with silver. In addition, Table 2 shows the mass concentration ratio of elements of the magnetic multilayer nanoparticles plated with silver obtained by the analysis of FIG.

実施例1で得られた置換型YIG粒子(Bi0.52.5Fe512)を分散処理し、その2gを塩化パラジウム(和光純薬製)0.1g/L、塩化錫(和光純薬製)10g/L、塩酸150ml/Lの水溶液1Lに浸漬させ、5分間攪拌処理し、固液分離後、硫酸50ml/Lの水溶液1Lに浸漬させ、5分間攪拌処理してパラジウムを担持させた。その後、再び固液分離し、硫酸銅(和光純薬製)10g/L、ホルマリン(和光純薬製)2g/L、EDTA−2Na(和光純薬製)20g/Lの溶液1Lに浸漬させ50℃、1時間攪拌処理し固液分離すると銅によりめっき被膜された磁性多層ナノ粒子2.6gが得られた。 The substituted YIG particles (Bi 0.5 Y 2.5 Fe 5 O 12 ) obtained in Example 1 were dispersed, 2 g of palladium chloride (manufactured by Wako Pure Chemical Industries, Ltd.) 0.1 g / L, tin chloride (manufactured by Wako Pure Chemical Industries, Ltd.) ) It was immersed in 1 L of an aqueous solution of 10 g / L and hydrochloric acid 150 ml / L and stirred for 5 minutes. After solid-liquid separation, it was immersed in 1 L of an aqueous solution of 50 ml / L sulfuric acid and stirred for 5 minutes to carry palladium. Thereafter, the solid and liquid are separated again and immersed in 1 L of a solution of 10 g / L of copper sulfate (manufactured by Wako Pure Chemical), 2 g / L of formalin (manufactured by Wako Pure Chemical), 20 g / L of EDTA-2Na (manufactured by Wako Pure Chemical). When the mixture was stirred for 1 hour at a temperature and separated into solid and liquid, 2.6 g of magnetic multilayer nanoparticles coated with copper were obtained.

本発明によれば、粒径がナノサイズの磁性粒子表面に金属又は金属酸化物の薄膜をナノサイズの厚さで均一に被覆させて磁性多層ナノ粒子とすることにより、磁気テープ等の磁気記録媒体、MOディスク、ホログラフィック体積記録用材料等の光磁気記録媒体、電子デバイス、静電気吸収特性を持つ磁性材料等、様々な磁性材料の原料とすることができ、高い磁気記録密度を有する、或いは超小型で強磁性を有する等、高性能で高機能な磁性材料を提供することが可能となる。   According to the present invention, magnetic recording of a magnetic tape or the like is performed by uniformly coating a metal or metal oxide thin film with a nano-sized thickness on the surface of a magnetic particle having a nano-sized particle size to form a magnetic multilayer nano-particle. It can be used as a raw material for various magnetic materials such as magneto-optical recording media such as media, MO disks, holographic volume recording materials, electronic devices, magnetic materials having electrostatic absorption characteristics, etc., and has a high magnetic recording density, or It becomes possible to provide a high-performance and high-performance magnetic material such as ultra-compact and ferromagnetic.

実施例1で生成した置換型YIGナノ粒子(Bi0.52.5Fe512)の電子顕微鏡画像である。2 is an electron microscopic image of substituted YIG nanoparticles (Bi 0.5 Y 2.5 Fe 5 O 12 ) produced in Example 1. FIG. 置換型YIGナノ粒子(Bi0.52.5Fe512)を酸化亜鉛で被覆した実施例2の磁性多層ナノ粒子の電子顕微鏡画像である。It is an electron microscope image of a substituted YIG nanoparticles (Bi 0.5 Y 2.5 Fe 5 O 12) a magnetic multilayer nanoparticles of Example 2 coated with zinc oxide. 置換型YIGナノ粒子(Bi0.52.5Fe512)を酸化亜鉛で被覆した実施例2の磁性多層ナノ粒子の電子顕微鏡画像である。It is an electron microscope image of a substituted YIG nanoparticles (Bi 0.5 Y 2.5 Fe 5 O 12) a magnetic multilayer nanoparticles of Example 2 coated with zinc oxide. 置換型YIGナノ粒子(Bi0.52.5Fe512)を酸化テルビウムで被覆した実施例3の磁性多層ナノ粒子を蛍光X線分析した測定結果図である。The substituted YIG nanoparticles (Bi 0.5 Y 2.5 Fe 5 O 12) a magnetic multilayer nanoparticles of Example 3 coated with terbium oxide is a measurement diagram of the fluorescent X-ray analysis. 置換型YIGナノ粒子(Bi0.52.5Fe512)を銀で被覆した実施例7の磁性多層ナノ粒子を蛍光X線分析した測定結果図である。The magnetic multilayered nanoparticles substituted YIG nanoparticles (Bi 0.5 Y 2.5 Fe 5 O 12) Example 7 was coated with silver is a measurement result showing that fluorescent X-ray analysis.

Claims (6)

粒径が1nm以上500nm以下の範囲にある磁性ナノ粒子の表面が、金属または金属酸化物の被膜で覆われていることを特徴とする磁性多層ナノ粒子。   A magnetic multilayer nanoparticle characterized in that the surface of a magnetic nanoparticle having a particle size in the range of 1 nm to 500 nm is covered with a metal or metal oxide film. 前記被膜の膜厚が、1nm以上100nm以下の範囲にあることを特徴とする請求項1に記載の磁性多層ナノ粒子。   2. The magnetic multilayer nanoparticle according to claim 1, wherein the thickness of the coating is in the range of 1 nm to 100 nm. 前記被膜が、Zn、Fe、Tb、Y、Ceの少なくとも1種の金属の酸化物を含むことを特徴とする請求項1又は請求項2に記載の磁性多層ナノ粒子。   The magnetic multilayer nanoparticle according to claim 1 or 2, wherein the coating contains an oxide of at least one metal selected from Zn, Fe, Tb, Y, and Ce. 前記磁性ナノ粒子が、一般式、Ax3-xyFe5-y12(式中、0≦x<3,0≦y<5であり、Aは、Bi、Ca、Ce、Pb、Ptの中から選ばれる1種以上の元素であり、Bは、Yまたは希土類元素の中から選ばれる1種以上の元素であり、Mは、Al、Co、Cr、Cu、Fe(II)、Ga、Ge、Hf、In、Li、Mn、Mo、Nd、Ni、Pb、Rh、Ru、Sc、Si、Sn、Ti、V、Zn、Zrの中から選ばれる一種以上の元素を示す。)で表される磁性体であることを特徴とする請求項1及至請求項3のいずれかに記載の磁性多層ナノ粒子。 The magnetic nanoparticles, the general formula, in A x B 3-x M y Fe 5-y O 12 ( where a 0 ≦ x <3,0 ≦ y < 5, A is, Bi, Ca, Ce, One or more elements selected from Pb and Pt, B is one or more elements selected from Y or rare earth elements, and M is Al, Co, Cr, Cu, Fe (II ), Ga, Ge, Hf, In, Li, Mn, Mo, Nd, Ni, Pb, Rh, Ru, Sc, Si, Sn, Ti, V, Zn, or Zr. The magnetic multilayer nanoparticle according to any one of claims 1 to 3, wherein the magnetic multilayer nanoparticle is represented by the following formula. 請求項1及至請求項4のいずれかに記載の前記磁性多層ナノ粒子で構成されることを特徴とする磁性材料。   A magnetic material comprising the magnetic multilayer nanoparticles according to any one of claims 1 to 4. 粒径が1nm以上500nm以下の範囲にある磁性ナノ粒子を形成するナノ粒子形成工程と、
無電解めっき法により、前記磁性ナノ粒子の表面に膜厚が1nm以上100nm以下の金属又は金属酸化物からなる被膜を形成する被膜形成工程と、
を含むことを特徴とする磁性多層ナノ粒子の製造方法。
A nanoparticle forming step of forming magnetic nanoparticles having a particle size in the range of 1 nm to 500 nm;
A film forming step of forming a film made of a metal or metal oxide having a film thickness of 1 nm or more and 100 nm or less on the surface of the magnetic nanoparticles by an electroless plating method;
The manufacturing method of the magnetic multilayer nanoparticle characterized by the above-mentioned.
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CN114023553A (en) * 2021-11-15 2022-02-08 山西大缙华磁性材料有限公司 Process method for manufacturing high-consistency sintered neodymium-iron-boron permanent magnet
CN115368127A (en) * 2022-08-22 2022-11-22 深圳顺络电子股份有限公司 Ferrite material, preparation method and common-mode inductor

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JP2011056365A (en) * 2009-09-08 2011-03-24 Toshiba Corp Porous carrier, composite porous adsorbent, method for adsorbing oil, method for purifying water and method for recovering valuable
KR101393542B1 (en) 2013-01-31 2014-05-27 한국기계연구원 Manufacturing apparatus of electroless nano particle co-precipitate using electro magnetic field
US9761357B2 (en) 2014-03-13 2017-09-12 International Business Machines Corporation Multi-layer magnetic nanoparticles for magnetic recording
US11043318B2 (en) 2014-03-13 2021-06-22 International Business Machines Corporation Multi-layer magnetic nanoparticles for magnetic recording
KR101976289B1 (en) * 2017-12-11 2019-05-07 경희대학교 산학협력단 Multifunctional particles and microfluid reaction system using the same
WO2021017216A1 (en) * 2019-07-29 2021-02-04 南京唐壹信息科技有限公司 High-frequency low-hysteresis manganese-zinc soft ferrite material and preparation method therefor
CN114023553A (en) * 2021-11-15 2022-02-08 山西大缙华磁性材料有限公司 Process method for manufacturing high-consistency sintered neodymium-iron-boron permanent magnet
CN115368127A (en) * 2022-08-22 2022-11-22 深圳顺络电子股份有限公司 Ferrite material, preparation method and common-mode inductor

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