| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a Mn-Zn-based ferrite which has a high relative initial magnetic permeability μ<SB>ir</SB>of ≥3,000 and exhibits a small temperature-attributed change in the relative initial magnetic permeability μ<SB>ir</SB>in the wide temperature range of -40°C to 100°C. <P>SOLUTION: The ferrite having a composition comprising, by mol, 52-53% Fe<SB>2</SB>O<SB>3</SB>and 20-22% ZnO, and the balance being mainly MnO, and characteristics that the relative initial magnetic permeability at 25°C, 10 kHz is 3,000-4,500 and the coefficient of variation of the relative initial magnetic permeability within a temperature range of -40 to 100°C is ≤10% is obtained by using, as a raw material, iron oxide fine particles characterized in that the median diameter obtained from the particle size distribution measured by the laser diffraction is ≤0.6 μm, the difference between 10% cumulative diameter in the particle size distribution and the median diameter is not higher than 2.0 times of the median diameter, and the primary particle diameter obtained from the specific surface area is ≤0.1 μm, then calcining a mixture of the iron oxide, MnO and ZnO, thereafter, forming and firing. <P>COPYRIGHT: (C)2005,JPO&NCIPI |
