MANUFACTURE OF OXIDE MAGNETIC MATERIAL

PURPOSE:To provide a method of manufacturing an oxide magnetic material, which attains the high sintered density, which is not attained by a conventional method, of a sintered body by controlling the powder body characteristics of raw calcined powder and obtains an MnZn soft ferrite, which has a high saturation magnetic flux density and moreover, has a low power loss. CONSTITUTION:An oxide magnetic material is manufactured by a method where in Fe, Mn and Zn are mixed in the form of an oxide solution, the obtained solution is sprayed in a spray calcinating furnace to obtain thermally decomposed calcinated powder and after the mean primary particle diameter of particles constituting the calcinated powder is controlled in a specified range of 0.3 to 0.7mum by a heat treatment (400 to 800 deg.C), the calcinated powder is granulated and molded, the partial pressure of oxygen at the time of heat-up is set at 0.5 to 2.0% and the powder is subjected to firing at the highest firing temperature of 1250 to 1320 deg.C, whereby a high-density sintered body is manufactured and an Mn-Zn soft ferrite having a high saturation magnetic flux density and a low power loss is obtained.