Electronic structure and magnetic moment of dilute transition metal impurities in semi-metallic CaB6

Abstract

Employing the all electron augmented plane wave+local orbital (APW+lo) method based on the density function theory (DFT), we have performed ab-initio calculations of electronic structure and magnetic properties of transition metal impurities doped in semi-metallic CaB6 host. Here, we present our results on the density of states (DOS), local magnetic moment and hyperfine field of 3d (Sc–Ni), 4d (Y–Pd) and 5d (La–Pt) in CaB6. Our results reveal strong localization of impurity d electrons yielding high local moments for most of the transition metal atoms, including the 5d atoms Ta, Re, Os and Ir. The results presented here would be useful towards a comprehensive understanding of the origin of weak ferromagnetism observed in CaB6. We believe that besides B or B6 vacancies which have been argued to be the main source of magnetism in CaB6, the local moments associated with different transition metal impurities can interact via conduction electron polarization and give rise to the weak ferromagnetism observed in this material.