Process for preparing polycrystalline ferrite materials and composites containing them

摘要

A ferrite composed of a polycrystalline ferrite which is obtained by sintering a ferrite starting powder by a discharge plasma technique is described. The ferrite starting powder is appropriately a coprecipitated ferrite powder. Prior to the sintering, the coprecipitated powder is preferably thermally treated or calcined at temperatures of not lower than 900 degrees C. A composite ferrite is also described, which is composed of the polycrystalline ferrite and a single crystal ferrite bonded together obtained by contacting the single crystal ferrite with the coprecipitated ferrite powder or embedding the single crystal ferrite in the powder, under which the polycrystalline ferrite powder is sintered by the discharge plasma sintering thereby bonding both ferrites together.