High temperature oxidation and its induced coercivity loss of a 2:17 type SmCo-based magnet

Journal Article · Sat Mar 07 04:00:00 EST 2015 · Journal of Applied Physics

DOI:https://doi.org/10.1063/1.4913876· OSTI ID:22413201

Wang, X. ^[1]; Zhao, H.; Wang, F. ^[1]; Guo, Zh.; Li, W. ^[2]

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1. Laboratory for Corrosion and Protection, Institute of Metal Research, Chinese Academy of Sciences, Shenyang 110016 (China)
2. Division of Functional Materials, Central Iron and Steel Research Institute, Beijing 100081 (China)

Oxidation has been explained as one possibility for unacceptable and irreversible coercivity loss of 2:17 type SmCo-based magnets at high temperatures over 550 °C, but the question for how oxidation affects coercivity in the magnet has not been fundamentally answered. In this work, oxidation and its induced degradation of the magnetic phases of a Sm(Co{sub bal}Fe{sub 0.22}Cu{sub 0.08}Zr{sub 0.02}){sub 7.5} magnet in air at 600 °C have been investigated by using transmission electron microscopy and correlated with the demagnetization curves measured. It shows that the coercivity loss, which is significantly increased with oxidation time, is small and independent of time in the magnet unaffected by oxidation. The reason lies in that the 2:17 cell and 1:5 cell boundary, although they have been completely disintegrated in the oxidized part by external oxidation of Co, Fe, and Cu and internal oxidation of Sm, remains in the unoxidized part except that 1:5 boundary close to the oxidized part is decreased in thickness and Cu content.

• OSTI ID: 22413201
• Journal Information: Journal of Applied Physics, Journal Name: Journal of Applied Physics Journal Issue: 9 Vol. 117; ISSN JAPIAU; ISSN 0021-8979
• Country of Publication: United States
• Language: English

Related Subjects

75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
COBALT
COERCIVE FORCE
COPPER
DEMAGNETIZATION
INTERMETALLIC COMPOUNDS
IRON
MAGNETIC MATERIALS
MAGNETS
OXIDATION
SAMARIUM
TRANSMISSION ELECTRON MICROSCOPY
ZIRCONIUM