Rapid loss of magnetic order in Ni on alloying with Cr, Mo, Re, and Si

Abstract

In this article, the variation of the Curie temperature Tc and the magnetic moment μ of Ni in the fcc alloys Ni1−xMx (M=Cr, Mo, Re, and Si) are reported for concentrations x between 0 and 15 at. %. The decrease of Tc and μ with x reported earlier for NiCr alloys are also observed for the NiMo, NiRe, and NiSi alloys. The initial rates of decreases are about 60 K/at. % for Tc and 0.05 μB/at. % for μ, leading to critical concentration xc≂13% above which ferromagnetism disappears. Qualitatively, these decreases may be understood in terms of transfer of outer shell electrons of M atoms to the 3d↓ band of Ni in the alloys. However, a quantitative calculation of xc is not yet available.