Calcined ferrite, and sintered ferrite magnet and its production method
AssigneeProterial, Ltd.
InventorsYasuaki Tanioku, Yushi Yoshimitsu, Yoshinori Kobayashi
Life of this patent
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Abstract
A sintered ferrite magnet having a composition of metal elements of Ca, R, A, Fe and Co, which is represented by the general formula of Ca1−x−yRxAyFe2n−zCoz, wherein R is at least one of rare earth elements indispensably including La; A is Sr and/or Ba; x, y, z and n represent the atomic ratios of Ca, R, A, Fe and Co; 2n represents a molar ratio expressed by 2n=(Fe+Co)/(Ca+R+A); and x, y, z and n meet the conditions of 0.15≤x≤0.35, 0.05≤y≤0.40, (1−x−y)>y, 0<z≤0.18, and 7.5≤(2n−z)<11.0.
Claims15
A sintered ferrite magnet having a composition of metal elements of Ca, R, A, Fe and Co, which is represented by the general formula of Ca1-x-y′RxAy′Fe2n-zCoz, wherein R is at least one of rare earth elements indispensably including La;
- A is Sr;
- x, y′, z and n represent the atomic ratios of Ca, R, A, Fe and Co;
- 2n represents a molar ratio expressed by 2n=(Fe+Co)/(Ca+R+A);
- and x, y′, z and n meet the following conditions:
- 0.425≤(1−x−y′)≤0.55,
- 0.15≤x≤0.35,
- 0.05≤y′≤0.40,
- (1−x−y′)>y′,
- 0<z≤0.18, and
- 7.5≤(2n−z)<11.0,
- wherein said sintered ferrite magnet further contains more than 0% and 1.0% or less by mass of Si as SiO2.
Dependencies are inferred from the claim text.