X-ray photoelectron spectroscopy and magnetism of Mn1−xAlxNi alloys

X-ray photoelectron spectroscopy (XPS), X-ray diffraction (XRD), magnetization and magnetic susceptibility of Mn_1−xAl_xNi alloys are reported. A change in the crystallographic structure takes place around x=0.4 from CuAuI to CsCl (B2) structure type. For x0.5 a mixed B2+L2₁ state exists which incorporates antiferromagnetic (B2) and ferromagnetic (L2₁) parts. A direct evidence for the existence of local moments on Mn sites in Mn_1-xAl_xNi alloys is given by the exchange splitting of XPS Mn 3s and Mn 2p3/2 core levels. The gradual filling of the Ni 3d band as the Al concentration increases can be explained by the hybridization of the Ni 3d band and Al 3sp states.