| 摘要 |
PROBLEM TO BE SOLVED: To provide a soft ferrite which has a high saturation magnetic flux density of Bs at a high temperature of 100 deg.C or higher, especially at a temperature of 150 deg.C or so and deteriorates its magnetic properties less (even if sacrificing its low power loss property to some extent) at the above high temperature, especially deteriorates its core loss less, and is superior in magnetic stability. SOLUTION: This manufacturing method includes burning process of obtaining a ferrite core by burning a molded body, and the burning process comprises a temperature rising step, a stable temperature step, and a temperature lowering step. When a ferrite core, containing 56 to 57 mol% iron oxide in terms of Fe2 O3 , 5 to 10 mol% zinc oxide in terms of ZnO, 3 to 6 mol% in terms of NiO, and the residual mol% manganese oxide in terms of (MnO) as the main components is manufactured, a holding temperature (stable temperature) is set at a temperature of 1,250 deg.C or higher in a stable temperature step, and the oxygen concentration of an atmosphere is set at 0.05 to 0.8%. |
