Electronic and magnetic properties of quaternary (Cu,Ni)MnSb alloys

Josef Kudrnovsky (1) , Vaclav Drchal (2) , Frantisek Maca (2) , Ilja Turek (3)

1 Theoretical
2 Theoretical
3 Institute of Physics of Materials AS CR

Magnetic properties and Curie temperatures of semi-Heusler alloys Cu$_{1-x}$Ni$_{x}$MnSb are calculated as a function of the alloy composition. The transition from the ferromagnetic state (NiMnSb) to the antiferromagnetic state (CuMnSb) gives rise to an abrupt change in the concentration dependence of alloy magnetization at about x$_{\rm Cu}=0.7$ while the Curie temperature decreases monotonically with the Cu-content. Such behavior can be understood as due to the onset of disorder in orientations of Mn-spins at x$_{\rm Cu}=0.7$. A simple account of magnetic disorder as based on the uncompensated disorder local moment picture provides also a good quantitative understanding of available experimental data.

Mots clés: Physical Sciences

Josef Kudrnovsky, Vaclav Drchal, Frantisek Maca, Ilja Turek. Electronic and magnetic properties of quaternary (Cu,Ni)MnSb alloys. Philosophical Magazine, 2008, 88 (18-20), pp.2739-2746. ⟨10.1080/14786430802232546⟩. ⟨hal-00513909⟩