Research on nanoscopic magnet including 3d transition metals

含3d过渡金属的纳米磁体研究

基本信息

批准号：
15510089
负责人：
ICHIYANAGI Yuko
金额：
$ 1.73万
依托单位：
Yokohama National University
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (C)
财政年份：
2003
资助国家：
日本
起止时间：
2003 至 2005
项目状态：
已结题

项目摘要

Magnetic properties of nanoparticles including 3d transition metals were investigated. Prepared samples were Co3O4, Mn3O4,Mn2O3, Ni-ferrite, NiZn-ferrite, Mn-ferrite, Mg-ferrite surrounded by amorphous SiO2.1.Co3O4 nanoaprticles with 3 nm in size showed ferromagnetic behavior below blocking temperature Tb, though bulk crystal has antiferromagnetic below TN=33 K.2.Magnetization of Mn3O4 nanoparticles showed drastic change depending on particle sizes. For 2.5 nm- sample was considered to be ordered periodically than other samples though the size was extremely small. This phenomenon could be confirmed by the results of XAFS measurements.3.NiO nanoparticles were produced by annealing Ni(OH)2 monolayer-nanoclusters above 973 K in air. In the magnetization measurements superparamagnetic or ferromagnetic behaviors were observed and characteristic properties of NiO nanoparticles were confirmed.4.Nil-xZnFe2O4(2<x<1) mixed ferrite nanoparticles encapsulated with amorphous SiO2 were prepared. Particle sizes were controlled to range from 2.6 nm to 33.7 nm by heat treatment, and the particle size dependence of saturation magnetization Ms was investigated for the x=0.5 region. The Ms value decreased abruptly for particle sizes. The relationship between saturation magnetizations Ms and the Zn concentration was almost similar to that between the saturation magnetization and Ni-Zn ferrite bulk crystal, however, the absolute values of Ms of the nanoparticles were about 30 % smaller than those of bulk crystal5.XAFS measurements and thermal analysis were also performed for all the samples. Functionalizing of medical application was newly considerd.

研究了包括3D过渡金属在内的纳米颗粒的磁性。准备好的样品的样品为CO3O4，MN3O4，MN2O3，Ni-Ferrite，Nizn-Ferrite，Mn-Ferrite，Mn- feriter，MN-GRITE，由无形Sio2.1.co3O4纳米帕特氏菌包围，其大小为3 nm，显示出尺寸为3 nm抗磁磁性低于Tn = 33 k.2. MN3O4纳米颗粒的碎磁化表现出巨大的变化，具体取决于粒径。对于2.5 nm的样品，尽管大小非常小，但被认为是定期排序的。 XAFS测量结果可以证实这种现象。3.Nio纳米颗粒是通过退火Ni（OH）2单层纳米群体在空气中973 K以上产生的。在磁化测量中，观察到了超磁或铁磁行为，并确认了Nio纳米颗粒的特征性能。4.NIL-XZNFE2O4（2 <x <1）混合铁矿纳米颗粒封装在用无用的Sio2封装的混合铁矿纳米颗粒。通过热处理将粒度控制至2.6 nm至33.7 nm，并研究了X = 0.5区域的饱和磁化磁化强度MS的粒径依赖性。 MS值突然减少了粒径。饱和磁化的MS与Zn浓度之间的关系几乎与饱和磁化和NI-ZN铁氧体大体晶体之间的关系，但是，纳米颗粒的MS的绝对值比Bulk Crystal5.xafs测量值小约30％。还为所有样品进行了热分析。新考虑的医疗应用功能化。