Matsushita Electric Industrial Co., Ltd.

Yasuyuki Aono

Osamu Inoue

Nobuya Matsutani

Koichi Kugimiya

Osamu Ishii

An oxide magnetic material provided by the present invention contains, as main components, 55 to 59 mol % of Fe.sub.2 O.sub.3 ; 35 to 42 mol % of MnO; and 6 mol % or less of ZnO, and further contains, as sub-components, 0.05 to 0.3 wt % of CaO; and 0.005 to 0.05 wt % of SiO.sub.2. The other oxide magnetic material provided by the present invention contains, as main components, 61 to 67 mol % of Fe.sub.2 O.sub.3 ; 3 to 36 mol % of MnO; and 30 mol % or less of ZnO, and further contains, as sub-components, 0.05 to 0.5 wt % of CaO; and 0.005 to 0.2 wt % of SiO.sub.2. Such materials can further contain one or more kinds of oxides selected from the group consisting of ZrO.sub.2, HfO.sub.2, Ta.sub.2 O.sub.5, Cr.sub.2 O.sub.3, MoO.sub.3, WO.sub.3, Al.sub.2 O.sub.3, Ga.sub.2 O.sub.3, In.sub.2 O.sub.3, GeO.sub.2, SnO.sub.2, Sb.sub.2 O.sub.3 and Bi.sub.2 O.sub.3. Such magnetic materials of the present invention have the advantages of having an extremely low magnetic loss even when used in the high frequency band and having a minimum magnetic loss at a temperature sufficiently higher than room temperature. Moreover, a switching power supply having a switching frequency of 300 kHz to 5 MHz is provided by using such magnetic materials as a magnetic core.

Growing community of inventors

Osaka, Japan

Yasuyuki Aono