Selforganization of Co and Fe nanoparticles in annealing process and their magnetic properties

Co和Fe纳米粒子在退火过程中的自组织及其磁性能

• 批准号: 18560643
• 负责人: TAKEDA Mahoto
• 金额: $ 2.34万
• 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: 2006
• 资助国家: 日本
• 起止时间: 2006 至 2007
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-18560643/
• 关键词: nano-scale magnetic particles; spontaneous formation; Lorentz Microscopy; SQUID measurement; 磁性微粒子; 自己組織化過程; TEM; 磁気特性

The present study investigated the spontaneous formation of nano-scale cobalt and iron particles in copper matrices, using Lorentz microscopy, high-resolution TEM, EELS analysis and SQUID measurements.1) Spherical iron, cobalt and iron-cobalt particles are formed at the initial stages of the precipitation. Although the spherical cobalt particles are transformed into cubic particles, iron particles have a less tendency to evolve in the shape, during the annealing.2) Iron nano-particles also make a pair-wise couplings, but the couplings were more ambiguous than Co pairs. On the contrary, spherical iron-cobalt complex particles are arranged along <100> orientations of copper matrices.3) The specimens receiving a short annealing shows a cusp at 40K, but they have another cusp around at 120K.4) Lorentz microscopy shows that the magnetic moment of the particles are oriented to 100 of copper matrices. The magnitudes of the moments are increased with the sizes, but there seem a critical size switching from fcc to bcc in structure.

本研究采用Lorentz显微镜、高分辨透射电镜、EELS分析和SQUID测量等方法，研究了纳米级钴和铁粒子在铜基体中的自发形成。1）球形铁、钴和铁钴粒子在沉淀初期形成。在退火过程中，球形钴粒子转变为立方粒子，而铁粒子的形状演变趋势较小。2）铁纳米粒子也产生了成对耦合，但耦合比钴对更模糊。3<100>）短退火样品在40 K时出现一个尖峰，在120 K附近出现另一个尖峰; 4）洛伦兹显微镜观察表明，铁钴复合物颗粒的磁矩取向为铜基体的100 °。矩的大小随尺寸的增大而增大，但在结构上存在由面心立方向体心立方转变的临界尺寸。

项目成果

Precipitation behavior of magnetic-particles in a Cu-Co alloy and their Magnetic properties

Cu-Co合金中磁性粒子的析出行为及其磁性能

• 发表时间: 2008
• 期刊: J. Jap. Inst. of Copper and Copper alloys 17(in press)
• 作者: Y. Tsuruta;M. Takeda;N. Wada;K. Kuwada;M. Takeguchi
• 通讯作者: M. Takeguchi

Lorentz Microscopy and Monte-Carlo calculation of Nano-scale particles

纳米级粒子的洛伦兹显微镜和蒙特卡罗计算

• 发表时间: 2007
• 作者: N. Wada;et. al.
• 通讯作者: et. al.

"Lorentz Microscopy and Monte-Carlo calculation of Nano-scale particles"

“纳米级粒子的洛伦兹显微镜和蒙特卡罗计算”

• 发表时间: 2007
• 期刊: Proc. 11th Loius Neel Conference
• 作者: M. Takeda;T. Tanabe;K. Hanawa;S. Yamamoto;高松久美子;N. Wada
• 通讯作者: N. Wada

History and Logics of Alloy Design

合金设计的历史和逻辑

• 发表时间: 2007
• 期刊: Muse Corporation
• 作者: M. Takeda;T. Tanabe;K. Hanawa;S. Yamamoto
• 通讯作者: S. Yamamoto

Cu-Fe合金におけるナノ磁性鉄微粒子の析出過程と磁気特性の関係

Cu-Fe合金中纳米磁性铁颗粒的析出过程与磁性能的关系

• 发表时间: 2006
• 作者: 高松久美子;他
• 通讯作者: 他