磁性材料 化学的共沈法によるＢａ‐Ｌａ‐Ｃｏ系Ｍ型フェライト微粒子の磁気特性

Abstract

Ba-La-Co M-type ferrite fine particles were prepared by the chemical coprecipitation process and a heat treatment. The chemical reagents used for the experiment were FeCl3⋅6H2O, BaCl2.6H2O, LaCl3⋅7H2O, and CoCl2.6H2O. The chemical coprecipitation process was applied to the samples having the formula {(BaO⋅n/2(Fe2O3))100-x-y(La2O3)x (CoO)y (n=7.0-12.0, x=1.0-10.0, y=1.0-10.0) the solution containing Ba2+, Fe3+, La3+, and Co2+ was poured into solution of NaOH (pH=13.0). The precipitated products were boiled for 2hs and they were carefully washed with water and dried. The obtained fine particles were heated at 950 to 1100°C for 2hs in air to obtain the single phase of Ba-La-Co M-type ferrite fine particles. The best magnetic properties were observed for the sample with the composition of {(BaO⋅n/2(Fe2O3))94.0(La2O3)3.0(CoO)3.0. The maximum values of magnetic properties were as follows: σ5=87.1×10-6 Wb⋅m/kg(69.3 emu/g), σr=42.9×10-6Wb⋅m/kg (34.1 emu/g), HCJ=469.5 kA/m (5.82 kOe) and TC= 456.4°C.