Magnetic phase transition and Mossbauer spectroscopy of ErNi2Mnx compounds

Authors

Jianli Wang, University of WollongongFollow
S J. Campbell, UNSWFollow
R Zeng, University of WollongongFollow
S. X. Dou, University of WollongongFollow
S J. Kennedy, Bragg Institute ANSTO Australia

RIS ID

37701

Publication Details

Wang, J. L., Campbell, S. J., Zeng, R., Dou, S. X. & Kennedy, S. J. (2011). Magnetic phase transition and Mossbauer spectroscopy of ErNi2Mnx compounds. Journal of Applied Physics, 109 (7), 07E304-1-07E304-3.

Abstract

Investigation of ErNi₂Mn_x with 0.90 ≤ x ≤ 1.10 indicates that the MgCu₂-type structure (with space group Fd-3m) is formed within x = 0.97−1.10. Curie temperature T_C = 50 K of ErNi2Mn is significantly higher than those of the corresponding ErNi₂ (T_C = 7 K) and ErMn₂ (T_C  = 15 K) compounds. Detailed analyses of DC magnetization data demonstrate that the magnetic phase transition at the Curie temperature is second order. The magnetic entropy change around T_C has been found to be 4.8 J/kg K for a magnetic field change of 0 to 5 T with its relative cooling power ∼283 J/kg. ⁵⁷Fe Mössbauer spectra below T_C have been fitted with three sub-spectra representing three inequivalent local magnetic environments while the paramagnetic spectra are fitted using two sub-spectra for two inequivalent crystal sites (8a and 16d), which supports the conclusion based on Rietveld refinement that Mn atoms occupy at both 8a and 16d sites.

Grant Number

ARC/DP0879070

Additional Grant Number

http://purl.org/au-research/grants/ARC/DP0879070