Half metallic ferromagnetism in ACaB (A = Li, Na and K) compounds-DFT study

Abstract

The electronic structure and magnetic properties of hypothetical ACaB compounds (A = Li, Na and K) in half-Heusler structure are investigated based on first principles calculations within the framework of density functional theory. It is found that for all the compounds the ferromagnetic state is more stable than nonmagnetic state. The calculations show that these compounds exhibit the half metallic ferromagnetic property with an integer magnetic moment of 2 μB per formula unit. The magnetic moment mainly originates from the spin polarization of B-p electrons and hybridization between B-p and Ca-d electrons. The absence of the transition-metal atoms makes these compounds important model systems for the study of the origin and properties of the half-metallic ferromagnetism of s-p electron systems.