Negative exchange interactions and Curie temperatures for Sm{sub 2}Fe{sub 17} and Sm{sub 2}Fe{sub 17}N{sub y}

Journal Article · Sat Feb 01 04:00:00 EST 1997 · Physical Review, B: Condensed Matter

DOI:https://doi.org/10.1103/PhysRevB.55.3670· OSTI ID:450385

Li, Z W; Morrish, A H ^[1]

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1. Department of Physics, University of Manitoba, Winnipeg, R3T 2N2 (CANADA)

M{umlt o}ssbauer spectra of Sm{sub 2}Fe{sub 17} and Sm{sub 2}Fe{sub 17}N{sub y} in a temperature range between 77 K and the Curie temperature have been studied. The exchange integrals, as a function of the distances between the Fe-Fe pairs, have been found by fitting the hyperfine field data at various temperatures for each Fe site. The results show that there exist both positive and negative exchange interactions for Sm{sub 2}Fe{sub 17} and Sm{sub 2}Fe{sub 17}N{sub y}. The magnitude of the negative interaction leads to a significant difference in the Curie temperature for the two materials. Based on a model that considers the competition between the positive and negative exchange interactions, the Curie temperatures of some 2:17-type compounds have been calculated; the results agree well with the experimental values. {copyright} {ital 1997} {ital The American Physical Society}

• OSTI ID: 450385
• Journal Information: Physical Review, B: Condensed Matter, Journal Name: Physical Review, B: Condensed Matter Journal Issue: 6 Vol. 55; ISSN PRBMDO; ISSN 0163-1829
• Country of Publication: United States
• Language: English

Related Subjects

66 PHYSICS
CRYSTAL DEFECTS
CURIE POINT
EXCHANGE INTERACTIONS
HYPERFINE STRUCTURE
IRON BASE ALLOYS
MOESSBAUER EFFECT
SAMARIUM ALLOYS
TEMPERATURE DEPENDENCE
TEMPERATURE RANGE 0065-0273 K