| 摘要 |
PROBLEM TO BE SOLVED: To provide an Mn base ferrite which reduces core loss and prevents reduction of first permeability ratio in a high-frequency region of more than about 1MHz, or preferably 3MHz or more. SOLUTION: A low loss oxide magnetic material contains 52-59mol% of Fe2 O3 as a basic ingredient, MnO as the rest of the basic ingredient except subsidiary ingredient and Ca oxide as sub-ingredient in terms of SiO2 and CaO: 0.005-1wt.% of SiO2 and 0.01-0.3wt.% of CaO. An average particle size of crystal grain of sintered material is 1-4μm. The crystal grain also exhibits a complex permittivity at 25 deg.C and 3MHz of 10<5> or less, a size of the real part μ' of a complex permeability at 25 deg.C and 1kHz of 500 or more, and a core loss at 3MHz, 25mT and a minimum core loss temperature of 500kw/m<3> . |
