Tdk Corporation

Masashi Ohmura

Shogo Muroya

Junichi Nagaoka

Jo Sato

Takuma Abe

A ferrite sinter magnet has a ferrite phase having a magnetoplumbite-type crystal structure, and contains at least a metal element A, a metal element R, Fe, Co, Zn, and B. The element A is at least one kind of element selected from the group consisting of Sr, Ba, Ca, and Pb, and essentially includes Ca. the element R is at least one kind selected from the group consisting of Bi and rare-earth elements including Y, and essentially includes La. Atomic ratios of the metal elements satisfy the following Expressions (1) to (5),ARFeCoZn  (1)0.40≤≤0.70  (2)8.20≤≤9.34  (3)0.05≤≤0.50  (4)0<≤0.20  (5) The content of Si is 0 to 0.60% by mass in terms of SiO, and the content of B is 0.1-0.70% by mass in terms of BO.

Ferrite sintered magnet, ferrite particles, bonded magnet, and rotating electrical machine

The magnet is a ferrite sintered magnet containing a ferrite phase having a magnetoplumbite-type crystal structure. The ferrite sintered magnet contains at least Ca, a metal element A, a metal element R, Bi, Fe, and a metal element M. The metal element A is at least one kind of element selected from the group consisting of Sr, Ba, and Pb, the metal element R is at least one kind of element selected from the group consisting of rare-earth elements including Y and essentially includes La, the metal element M is at least one kind of element selected from the group consisting of Co, Ni, Zn, Al, Cu, and Cr, and essentially includes Co, and when an atonic ratio of the metal elements is expressed by Formula (1), c, a, r, b, f, and m in Formula (1) satisfy the following Expressions (2) to (8).

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Tokyo, Japan

Masashi Ohmura