Electronic structure and magnetic properties of dilute Cr alloys with transition-metal impurities

Abstract

By using full-potential linearized augmented plane wave (FLAPW) method based on the density function theory (DFT), we have performed ab initio calculations of electronic structure and magnetic properties for dilute alloys of Cr with transition metals. Here, we present our results for the local magnetic properties of $3d$ (Sc\char21{}Ni) and $4d$ (Y\char21{}Pd) impurities in Cr, as well as changes in macroscopic properties such as total magnetization and specific heat of Cr alloys, arising from impurity-induced host perturbations. Results obtained for nonmagnetic local density of states is analyzed within Stoner model, and the condition for local moment formation is found to be satisfied only for Fe, Co, and Ni. For all other cases including Mn, the impurity moments are predicted to be induced by Cr host. Systematic trends for the impurity local moments and hyperfine fields in antiferromagnetic Cr host have been established. The trends show remarkable similarity with those observed in ferromagnetic Fe, Co, and Ni hosts. While the impurity moments for Sc, Ti, V, and Mn are found to be antiparallel with respect to the near neighbor Cr moment, self-consistent solutions for Fe, Co, and Ni show ferromagnetic coupling. For $4d$ impurities, except for Rh and Pd, the exchange interaction remain antiferromagnetic. The calculated changes of the total moment due to host perturbations show qualitative agreements with data from magnetization measurements. A detailed comparison is made for the impurity-induced changes in the total density of states at Fermi energy ${E}_{F}$ and experimentally measured electronic specific heat of Cr alloys. The results presented in this work provide comprehensive and improved understanding of electronic and magnetic properties of dilute Cr alloys. They are also useful for a common understanding of local magnetic properties of transition metal impurities in ferromagnetic and antiferromagnetic hosts.