Patent ID: 6955768
Filing Date: 2005-10-18
Classification: C01G,C01P,C04B,G11B,H01F,Y10T

Abstract:
1. A method of making a ferrite calcined body, the method comprising the steps of: preparing a material powder mixture by mixing: a material powder of at least one compound that is selected from the group consisting of SrCO calcining the material powder mixture at a temperature of 1,100° C. to 1,450° C., thereby forming a ferrite calcined body having an M-type magnetoplumbite structure and a composition represented by the general formula: where A is at least one element selected from the group consisting of Sr, Ba, Pb and Ca; R is at least one element selected from the group consisting of the rare-earth elements (including Y) and Bi and always includes La; 0.05≦x<0.3; and 5.0≦n≦6.5; preparing another material powder mixture by mixing an oxide material powder of at least one element selected from the group consisting of Co, Ni, Mn and Zn and a material powder of Fe calcining the material powder mixture at a temperature of 700° C. to 1,450° C., thereby forming a ferrite calcined body having a spinel-type structure and a composition represented by the general formula: where M is at least one element selected from the group consisting of Co, Ni, Mn and Zn; and preparing a calcined body by adding the ferrite calcined body having the spinel-type structure at 0.2 wt % to 6.2 wt % to the ferrite calcined body having the M-type magnetoplumbite structure.