Mössbauer, magnetic, and electronic-structure studies of YFe_12-xMo_x compounds

Authors

I.A. Al-Omari, University of Nebraska - Lincoln
Sitaram Jaswal, University of NebraskaFollow
A.S. Fernando, University of Nebraska - Lincoln
David J. Sellmyer, University of Nebraska-LincolnFollow
H.H. Hamdeh, Department of Physics, Wichita State University, Wichita, Kansas

Document Type

Article

Date of this Version

November 1994

Comments

Published by American Physical Society. Phys. Rev. B 50, 12,665 (1994). http://prb.aps.org. Copyright © 1994 American Physical Society. Permission to use.

Abstract

Mössbauer spectra, magnetization measurements, and self-consistent spin-polarized electronic structures of YFe_12-xMo_x, where x=0.5, 1.0, 2.0, 3.0, and 4.0, are reported. The ternary compounds YFe_12-xMo_x have the crystalline tetragonal ThMn₁₂ structure. Analyses of the Mössbauer spectra show that Mo atoms occupy the 8i Fe sites of the ThMn₁₂ structure, in agreement with previous observations. Room-temperature magnetic and Mössbauer measurements show that the compounds with x≤2.0 are ferromagnetic and with x≥3.0 are paramagnetic. Measurements at 25 K show that all the samples are magnetically ordered. The magnetic hyperfine field is found to decrease with increasing Mo concentration, which is in qualitative agreement with the calculated magnetic moments. The calculated magnetization decreases less rapidly with increasing x than the experimental data. In general the data suggest that with increasing Mo concentration there is an increase of antiferromagnetic coupling among the Fe moments, which leads to cluster-glass or spin-glass-like phenomena. The measured isomer shift relative to α-iron is found to decrease linearly with x.