Crystal Structure and Microstructural Control of Z-type Hexaferrite (Ba,Sr,La)3Co2Fe24O41 by Molten Salt Synthesis

초록

? Almost single-phase Z-type hexaferrite Ba 3 Co 2 Z and Ba 1.5 Sr 1.5 Co 2 Z can be synthesized, however, Ba 1.5 La 1.5 Co 2 Z was synthesized with M- and T-type hexaferrites. ? When the calcination temperature is 1,040℃ and the molten salt synthesis temperature is 1,150℃, Z-type particles suitable for electromagnetic shielding can be made. ? The higher the molten salt synthesis temperature, the lower the Aspect ratio, so the particles at 1,150℃ rather than 1,200℃ are better. ? The calcination temperature has to be considered to avoid agglomeration and suppress formation of a spinel phase (CoFe 2 O 4 ) after annealing with molten salt. ? The calcination temperature has to be controlled not to form spinel phase (CoFe 2 O 4 ) to obtain single-phase Ba 1.5 La 1.5 Co 2 Z.