Hexagonal Ferrite 에 관한 연구 (IV)

In order to obtain the fundamental data for the preparation of ferroxplana Zn₂Y (Ba₂Zn₂Fe 12 O 22 ), which is useful for GHz-band communication, the optimum coprecipitation condition of Zn(NO₃)₂-6FeCl₃ in NH₄OH solution and the formation process of the hexagonal ferrites were investigated. By the hot-petroleum-drying and calcining the coprecipitated hydroxide mixture Zn(OH)₂+Ba(OH)₂+6Fe(OH)₃, the fine and uniform powder was obtained, whose phase composition and microstructure were studied by X. R. D. and electron microscope. In results, it was found that Zn₂Y, BaM, and Zn₂W were the representative phases in calcined specimens whose activation energies of crystal growth were about 3.8, 2.5, 5.4×10⁴ J/mole, respectively. The sintered specimens would be appreciated as useful magnetic cores for the high frequency communication.