Nippon Ferrite, Ltd.

Hitachi Ferrite, Ltd.

Hitoshi Ueda

Norikazu Koyuhara

Takashi Tsuboi

Emi Nakagawa

Akio Uchikawa

A Ni ferrite sintered body comprising 48.0-50.0 mol % of Fe.sub.2 O.sub.3, 14.0-24.0 mol % of NiO and 28.0-36.0 mol % of ZnO with 50 ppm or less of P as an impurity, the sintered body having a minimum core loss of 30 kW/m.sup.3 or less at 50 kHz and 50 mT, and the segregation percentage of P in the crystal structure being 1% or less by area. The Ni ferrite sintered body preferably has an average crystal grain size of 3-30 .mu.m, the percentage of crystal grain particles larger than two times the average crystal grain size being preferably 10% or less based on the total number of the crystal grain particles in a crystal structure.

Ni ferrite and core made of Ni ferrite for power supplies

A dielectric ceramic composition having a high relative dielectric constant a high quality factor and a small temperature coefficient of resonance frequency, consisting essentially of calcium oxide, strontium, oxide, bismuth oxide and titanium oxide, and having a composition represented by the formula:

Growing community of inventors

Tottori, Japan

Hitoshi Ueda