鉄ナノ粒子表面構造制御による新規強磁性材料の創成

抄録

In order to fabricate the high performance permanent magnet, we had prepared the following materials as the precursor of nanocomposite magnet by using core-shell structure with Fe phase as soft phase and ε-Fe₂O₃ phase as hard phase. In order to prepare air-stable metallic Fe nanoparticles, iron-oxide nanoparticles as precursors were reduced in a hydrogen atmosphere and then their surfaces were oxidized under low concentration of oxygen. To obtain Fe₂O₃ phase, we treated iron oxide nanoparticles with silica shell at several temperature. The size of magnetic nanoparticles affects their magnetism. We had also controlled the particle size and crystal structure.