| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide an Mn-Zn-Co system ferrite iron core material which is low in loss in a frequency of some hundreds kHz or so, and excellent in temperature performance and production stability. <P>SOLUTION: The material contains Fe<SB>2</SB>O<SB>3</SB>: 50-55 mol%, CoO: 0.05-0.8 mol%, ZnO: 6-14 mol%, and MnO: 32-40 mol%, and it satisfies (1) formula: 54.4≤[Fe<SB>2</SB>O<SB>3</SB>(mol%)]+[CoO (mol%)]+0.2[ZnO (mol%)]≤56.4, and (2) formula: 0.10[Fe<SB>2</SB>O<SB>3</SB>(mol%)]-5.08≤[CoO (mol%)]≤0.02[Fe<SB>2</SB>O<SB>3</SB>(mol%)]-0.04[ZnO (mol%)]. A loss minimum temperature Tmin (°C), measured at a maximum magnetic flux density 200 mT and a frequency of 100 kHz, is 60-120°C. A temperature coefficient α of (3) formula: temperature coefficient α=äPcv(Tmin-20)-Pcv(Tmin-60)}/40 is negative, and an absolute value is less than 3.5 kW/m<SP>3</SP>/°C. <P>COPYRIGHT: (C)2007,JPO&INPIT |
