For high frequency power source low loss MnZn ferrite and it is low production manner null of loss MnZn

摘要

PURPOSE:To obtain small loss characteristics easily by sintering a raw material mainly composed of ferrite oxide, manganese oxide and zinc oxide at 1250-1400 deg.C, by holding the raw material for 20-360 minutes at the temperature of 1100-1250 deg.C in 0.001-20% oxygen partial pressure atmosphere and thereafter cooling the raw material in a nitrogen atmosphere. CONSTITUTION:After 53ml% iron oxide (alphaFe2O3), 35ml% manganese oxide(MnO) and 12ml% zinc oxide(ZnO) are calcined in air and pulverized and then granulated, for example a toroidal molded body is obtained from the granulated product by an oil hydraulic press. This molded body is calcined by the following method: For example, a temperature is raised at the rate of 200 deg.C/h, the molded body is held at 1310 deg.C for three hours and thereafter the temperature is lowered to a predetermined temperature (T1) at the rate of 200 deg.C/h. After the molded body is held for one hour at that temperature (T1) in the predetermined oxygen partial pressure atmosphere (PO2) so that a divalent iron concentration is controlled, the atmosphere is changed to a nitrogen atmosphere and a furnace cooling is conducted subsequently. Thus, the divalent iron concentration can optimally be controlled and the substantial improvement of a loss is performed easily.