Structural and magnetic properties of Nd{sub 2}Fe{sub 17{minus}{delta}}Cr{sub {delta}} ({delta}=0, 0.5, 1, 1.9)
- Department of Physics, Centre for the Physics of Materials, McGill University, 3600 University Street, Montreal, Quebec, H3A 2T8 (CANADA)
In Nd{sub 2}Fe{sub 17{minus}{delta}}Cr{sub {delta}} ({delta}=0, 0.5, 1, 1.9), Cr substitutes for Fe atoms without changing the crystal structure. Neutron diffraction measurements show that for all values of {delta}, Cr preferentially substitutes for Fe in the 6 c site and randomly substitutes for Fe in the 18 f site. Cr substitution can be explained by considering the enthalphy of mixing using Miedema{close_quote}s model. The Nd{endash}Cr enthalphy of mixing is positive and this causes preferential substitution of Cr in those sites that have the lowest number of Nd nearest neighbors, i.e., the 6c site. Upon Cr substitution the Curie temperature increases from 327 K up to 374 K for {delta}=1 and then decreases to a value of 356 K for {delta}=1.9. This anomalous behavior can be qualitatively explained by two competing mechanisms arising from the decrease in the number of 6c-6c Fe pairs with increasing Cr concentration and from the decrease in volume of Nd{sub 2}Fe{sub 17{minus}{delta}}Cr{sub {delta}} with increasing {delta} which affects the 6c-6c interatomic Fe distances. {copyright} {ital 1997 American Institute of Physics.}
- OSTI ID:
- 496557
- Report Number(s):
- CONF-961141--
- Journal Information:
- Journal of Applied Physics, Journal Name: Journal of Applied Physics Journal Issue: 8 Vol. 81; ISSN JAPIAU; ISSN 0021-8979
- Country of Publication:
- United States
- Language:
- English
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