Neutron diffraction study of MnNiGa2—structural and magnetic behaviour

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. © 2014,AIP Publishing LLC.

Description

Proceedings of the 55th Annual Conference on Magnetism and Magnetic Materials, 14-18 November 2010, Atlanta, Georgia.

Keywords

Ferromagnetic materials, Atoms, Isothermal processes, Magnetism, Magnetic properties, Temperature monitoring

Citation

Wang, J. L., Ma, L., Hofmann, M., Avdeev, M., Kennedy, S. J., Campbell, S. J., Md Din, M. F., Hoelzel, M., & Dou, S. X. (2014). Neutron diffraction study of MnNiGa2—structural and magnetic behaviour. Paper presented at the 55th Annual Conference on Magnetism and Magnetic Materials, 14-18 November 2010, Atlanta, Georgia. In Journal of Applied Physics, 115(17), 17A904. doi:10.1063/1.4857455