Magnetocaloric effect and magnetostructural coupling in Mn0.92Fe0.08CoGe compound

Authors

Jianli Wang, University of WollongongFollow
Precious Shamba, University of WollongongFollow
Wayne D. Hutchison, University of New South Wales
Qinfen Gu, Australian Synchrotron Company
M F. Md Din, University of WollongongFollow
Q Y. Ren, University of New South Wales
Zhenxiang Cheng, University of WollongongFollow
Shane J. Kennedy, ANSTO, Bragg Institute, AnstoFollow
Stewart J. Campbell, University of New South WalesFollow
S X. Dou, University of WollongongFollow

RIS ID

97911

Publication Details

Wang, J. L., Shamba, P., Hutchison, W. D., Gu, Q. F., Md Din, M. F., Ren, Q. Y., Cheng, Z. X., Kennedy, S. J., Campbell, S. J. & Dou, S. X. (2015). Magnetocaloric effect and magnetostructural coupling in Mn0.92Fe0.08CoGe compound. Journal of Applied Physics, 117 (17), 17D103-1-17D103-4.

Abstract

The structural properties of Mn_0.92Fe_0.08CoGe have been investigated in detail using synchrotron x-ray diffraction in zero and applied pressure (p = 0-10 GPa). A ferromagnetic transition occurs around T_C = 300 K and a large magnetic-entropy change −ΔS_M = 17.3 J/kg K detected at T_C for a field change of ΔB = 5 T. The field dependence of −ΔS _M ^max can be expressed as −ΔS _M ^max ∝ B. At ambient temperature and pressure, Mn_0.92Fe_0.08CoGe exhibits a co-existence of the orthorhombic TiNiSi-type structure (space group Pnma) and hexagonal Ni ₂In-type structure (space group P63/mmc). Application of external pressure drives a structure change from the orthorhombic TiNiSi-type structure to the hexagonal Ni ₂In-type structure. A large anomaly in heat capacity around T_C is detected and the Debye temperature θ_D (=319(±10) K) has been derived from analyses of the low temperature heat capacity, T ≲ 10 K.

Grant Number

ARC/DP110102386

Additional Grant Number

http://purl.org/au-research/grants/arc/DP110102386