Cu-substitution effects on the magnetic properties of weak itinerant electron ferromagnet CrAlGe

Cu-substitution effects on ferromagnetism in Cr-base ternary alloy CrAlGe with an orthorhombic TiSi2-type structure was investigated. The lattice parameters of Cr0.95Cu0.05AlGe were a = 4.748 Å, b = 8.209 Å and c = 8.696 Å at room temperature. The spontaneous and effective moment were determined to be ps = 0.533 μB/f.u at 5 K and peff = 1.89 μB/f.u, respectively. The Curie temperature TC was estimated to be 108 K. These ps and TC of Cr0.95Cu0.05AlGe were larger than those of CrAlGe and Ti-substituted compound. The peff/ps was determined to be 3.55, which was smaller than that of CrAlGe and Ti-substituted compound. Obtained results suggest that the substitution of Cu for Cr in CrAlGe leads suppression of its weak itinerant electron ferromagnetism.