Neutron diffraction study of MnNiGa2 - Structural and magnetic behaviour

Authors

Jianli Wang, University of WollongongFollow
L Ma, Chinese Academy of Science
M Hofmann, Technische Universitat Munchen
M Avdeev, ANSTO
S J. Kennedy, ANSTO
S J. Campbell, University of New South WalesFollow
M F. Md Din, University of WollongongFollow
M Hoelzel, Technische Universitat Munchen
G H. Wu, Chinese Academy of Science
S X. Dou, University of WollongongFollow

RIS ID

87661

Publication Details

Wang, J. L., Ma, L., Hofmann, M., Avdeev, M., Kennedy, S. J., Campbell, S. J., Md Din, M. F., Hoelzel, M., Wu, G. H. & Dou, S. X. (2014). Neutron diffraction study of MnNiGa2 - Structural and magnetic behaviour. Journal of Applied Physics, 115 (17), 17A904-1-17A904-3.

Abstract

MnNiGa2 crystallizes in the L21 (Heusler) structure and has a ferromagnetic ordering temperature TC ∼ 192 K. Rietveld refinement of the neutron diffraction patterns indicates that the Ga atoms occupy the equivalent 8c position, while Mn and Ni share the 4a (0, 0, 0) and 4b (0.5, 0.5, 0.5) sites with a mixed occupancy of Mn and Ni atoms. It is found that that ∼83% of Mn and ∼17% Ni are located at the 4a site while ∼83% of Ni and ∼17% Mn occupy the 4b site. There is no evidence of a magneto-volume effect around TC. In agreement with this finding, our detailed critical exponent analyses of isothermal magnetization curves and the related Arrott plots confirm that the magnetic phase transition at TC is second order.