Temperature-compensated Pr sub 1 minus x minus y Sm sub x R sub y Co sub 5 minus. delta. permanent magnets (R=Er, Dy, Ho, Gd, and Tb; x =0. 24; y =0. 2, 0. 3, and 0. 4)

Journal Article · Tue May 01 04:00:00 EDT 1990 · Journal of Applied Physics; (USA)

DOI:https://doi.org/10.1063/1.344846· OSTI ID:7123697

Velu, E M.T.; Obermyer, R T; Sankar, S G; Wallace, W E ^[1]

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1. Mellon Institute, Carnegie Mellon University, Pittsburgh, PA (USA) Metallurgical Engineering and Materials Science Department, Carnegie Mellon University, Pittsburgh, Pennsylvania 15213 (USA)

Application of permanent magnets in devices such as traveling wave tubes requires a high degree of flux stability over a wide temperature range ({minus}50 to 150 {degree}C). PrCo{sub 5}-based permanent magnets with near zero temperature coefficient of remanence ({alpha}) can be fabricated by the substitution of a suitable heavy rare-earth element for Pr in Pr{sub 1{minus}{ital x}{minus}{ital y}}Sm{sub {ital x}}R{sub {ital y}}Co{sub 5} (R=Er, Dy, Ho, Gd, or Tb). Pr{sub 0.76{minus}{ital y}}Sm{sub 0.24}R{sub {ital y}}Co{sub 5} magnets with {ital y}=0.2, 0.3, and 0.4 and R=Er, Dy, Ho, Gd, and Tb were fabricated and the temperature coefficient of remanence ({alpha}) and the temperature coefficient of coercivity ({beta}) were determined. Among all the heavy rare-earth elements examined, the substitution of Er resulted in magnets with maximum {ital B}{sub {ital r}} and ({ital BH}){sub max} at all temperatures (22--150 {degree}C). Magnets with the substitution of Gd exhibited the highest {ital H}{sub {ital ci}} at all temperatures. The substitution of Dy and Tb gave magnets with low values for {ital B}{sub {ital r}} and ({ital BH}){sub max}. Optimally processed magnets with a typical composition Pr{sub 0.46}Sm{sub 0.24}Er{sub 0.3}Co{sub 4.6} exhibited {ital B}{sub {ital r}} =8000 G, {ital H}{sub {ital ci}} =15 800 Oe, ({ital BH}){sub max} =16 MG Oe at room temperature, and {alpha}={minus}0.015 (%/ {degree}C) and {beta}={minus}0.34 (%/ {degree}C) over the temperature range 22--150 {degree}C.

• OSTI ID: 7123697
• Journal Information: Journal of Applied Physics; (USA), Journal Name: Journal of Applied Physics; (USA) Vol. 67:9; ISSN 0021-8979; ISSN JAPIA
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360104* -- Metals & Alloys-- Physical Properties
ALLOYS
COBALT ALLOYS
COERCIVE FORCE
FABRICATION
MAGNETIC PROPERTIES
MAGNETS
PERMANENT MAGNETS
PHYSICAL PROPERTIES
PRASEODYMIUM ALLOYS
RARE EARTH ALLOYS
SAMARIUM ALLOYS
TEMPERATURE DEPENDENCE