| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide NiMnZn-system ferrite which is dramatically increased in saturation flux density while remarkably reduced in magnetic loss compared with a conventional one, and to provide its manufacturing method. <P>SOLUTION: The NiMnZn-system ferrite contains, as main components, 55.0 to 61.5 mol% of a ferric oxide in terms of Fe<SB>2</SB>O<SB>3</SB>, 2.5 to 7.5 mol% of a nickel oxide in terms of NiO, 4.5 to 15.5 mol% of a zinc oxide in terms of ZnO, and a manganese oxide (in terms of MnO) for the remaining part. The NiMnZn-based ferrite uses material powder having a specific surface area of 3.0 m<SP>2</SP>/g or larger (measured by the BET method) as a material of NiO, one of the main components, and is manufactured by burning. The NiMnZn-based ferrite has a saturation flux density Bs of 470 mT or higher (measured in a magnetic field of 1194 A/m) at 100°C and a magnetic loss Pcv of 790 kW/m<SP>3</SP>or smaller (measured at 100 kHz and 200 mT) at 100°C, and satisfies a relationship between the saturation flux density Bs and the magnetic loss Pcv which is expressed by an expression (1): Pcv≤(11.201)×Bs-4901.3. <P>COPYRIGHT: (C)2009,JPO&INPIT |
