Gdイオン置換によるZ型フェライトの高周波初透磁率の改善 : ソフト磁性材料

概要

論文の詳細を見る
Ceramics made from a series of room-temperature ferrimagnetic mixed oxides, Ba_3Co_2Gd_xFe_<24-x>O_<41> (x = 0-1.0), with Z-type structure, were prepared by the conventional powder metallurgy method. A series of Ba_3Co_2Gd_xFe_<24-x>O_<41> samples were made with BaCO_3, CoO, Gd_2O_3, and α-Fe_2O_3 as starting materials. The frequency dependence of the initial permeability of all samples was measured. The initial permeability of Ba_3Co_2Gd_<0.1>Fe__<23.9_>O_<41> was 22.3 (at 0.1 GHz), which was the highest of all the samples. It was a remarkably high value compared with those reported for isotropic samples. The crystal structure was determined by the x-ray diffraction method; a single phase of the Z-type structure was obtained for Ba_3Co_2Gd_xFe_<24-x>O_<41> (x = 0.01, 0.1). Gadolinium ions formed a solid solution of Co_2Z ferrite. This is one of the reasons for the high initial permeability. The other reasons are higher densification and the change in magnetic anisotropy caused by a small quantity of Gd ions forming a solid solution of the Z-phase.
社団法人日本磁気学会の論文
2002-04-01