Sm-Fe-N ALLOY POWDER AND PROCESS FOR THE PRODUCTION THEREROF

Title:

Sm-Fe-N ALLOY POWDER AND PROCESS FOR THE PRODUCTION THEREROF

Document Type and Number:

WIPO Patent Application WO/1999/033597

Kind Code:

A1

Abstract:

A magnetic powder of an Sm-Fe-N alloy, which has a mean particle diameter of 0.5 to 10 $g(m)m, and either an average acicularity of 75 % or above or an average sphericity of 78 % or above. The powder exhibits an extremely high residual magnetization and an extremely high coercive force, since particles characterized by the above acicularity or sphericity have particle diameters approximately equal to that of the single domain particle and nearly spherical particle shapes. The powder can be produced by preparing an Sm-Fe oxide by firing a coprecipitate corresponding to the oxide, mixing the obtained oxide with metallic calcium and subjecting the mixture to reduction/diffusion and nitriding successively.

Inventors:

KAWANO YOSHIYUKI (JP)
KUME MICHIYA (JP)
ICHINOMIYA KEIJI (JP)

Application Number:

PCT/JP1998/005846

Publication Date:

July 08, 1999

Filing Date:

December 24, 1998

Export Citation:

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Assignee:

NICHIA KAGAKU KOGYO KK (JP)
KAWANO YOSHIYUKI (JP)
KUME MICHIYA (JP)
ICHINOMIYA KEIJI (JP)

International Classes:

B22F1/00; B22F9/20; C01B21/06; B22F9/22; C22C32/00; H01F1/053; H01F1/059; (IPC1-7): B22F1/00; B22F9/20; H01F1/059

Foreign References:

JPH06151127A	1994-05-31
JPH06346101A	1994-12-20
JPH05315174A	1993-11-26
JPH06212342A	1994-08-02
JPH08188803A	1996-07-23

Other References: