| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide an inexpensive ferrite magnet that has excellent magnet characteristics even in a compositional region which is more excessive in Fe<SB>2</SB>O<SB>3</SB>than the stoichiometric composition. <P>SOLUTION: In the ferrite magnet, the main phase of a magnetoplumbite type crystal structure expressed by the chemical formula of (A<SB>1-x</SB>R<SB>x</SB>)O-n[(Fe<SP>3+</SP><SB>1-y</SB>Fe<SP>2+</SP><SB>y</SB>)<SB>2</SB>O<SB>3</SB>] occupies ≥80% in mole ratio. In the chemical formula, A denotes at least one kind of elements selected out of Ba and Sr and invariably contains Ba, and R denotes at least one kind of elements selected from among rare-earth elements. In addition, x, y, and n respectively denote mole ratios and adjusted to satisfy: 0<x≤0.6, 0<y≤0.05, and 6.0<n≤6.6. At the time of sintering the ferrite magnet, the reducing atmosphere is controlled so that the main phase may be produced by ≥80% in mole ratio. <P>COPYRIGHT: (C)2005,JPO&NCIPI |
