Ferrite sintered magnets, ferrite particles, bonded magnets, and rotating electric machines

摘要

PROBLEM TO BE SOLVED: To provide ferrite particles having low magnetic characteristics depending on sintering temperature, ferrite sintered magnets and the like. A ferrite sintered magnet 100 has a ferrite phase 4 having a magnetoplumbite-type crystal structure and a grain boundary phase 6. This magnet contains elements R, elements M, Fe, Co, B, Mn and Cr. The element R is at least one element selected from rare earth elements including Y, and the element M is at least one element selected from the group consisting of Ca, Sr and Ba, and always contains Ca and is a metal. When the atomic composition of the element is expressed as R1-xMxFem-yCoy, x, y and m satisfy the following formula. 0.2 ≦ x ≦ 0.8 (1) 0.1 ≦ y ≦ 0.65 (2) 3 ≦ m 14 (3) Further, the B content is 0.1 to 0.4% by mass in terms of B2O3. The Mn content is 0.15 to 1.02% by mass in terms of MnO, and the Cr content is 0.02 to 2.01% by mass in terms of Cr2O3. [Selection diagram] Fig. 1