The relationship between microstructure and magnetic properties of nano-scale magnets formed in a copper matrix

2015 Fiscal Year Final Research Report

• Project/Area Number: 25420689
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Research Field: Physical properties of metals/Metal-base materials
• Research Institution: Yokohama National University
• Principal Investigator: TAKEDA Mahoto 横浜国立大学, 工学(系)研究科(研究院), 准教授 (30188198)
• Co-Investigator(Renkei-kenkyūsha): HIROI Zenji 東大, 物性研究所, 教授 (30192719)
• Project Period (FY): 2013-04-01 – 2016-03-31
• Keywords: ナノ磁性体 / 磁気特性 / 微視的組織 / 磁区構造 / 熱磁気特性

Outline of Final Research Achievements

This study has investigated the relationship between microstructural evolution and magnetic properties　of magnetic particles formed in Cu-Ni-X alloys.Single crystal Cu-Ni-X alloy samples were prepared and used for high-resolution transmission and photoemission electron microscopy(TEM and PEEM) observations.The first principle electron energy band calculations and micromagnetic　simulations based on KKR method and Landau-Lifschitz-Gilbert equation were also implemented.The present TEM and PEEM observations have revealed that Ni-Fe rich tiny particles were distributed randomly in copper matrix in the initial stage of annealing, while the tendency to arrange linear along <100> directions became more clear with further annealing. A ferromagnetic particle with a magnetically single-domain formed anti-parallel spin pair with an adjacent particle. The A-C mode M-T susceptibility measurements suggest that two types of ferromagnetic regions were formed just after the solution-treatment.

Free Research Field

金属物性、電子顕微鏡結晶学