Spin-polarized optical properties of half-metallic binary XBi (X = Ca, Sr and Ba) compounds in zinc blende and wurtzite phases

Abstract

In this work, we aim to study the spin-polarized optical properties of the non-transition metal-based binary compounds XBi (X = Ba, Sr and Ca) in the zinc blende and wurtzite phases. The calculations are performed by the developed full-potential augmented plane wave plus local orbitals (FP-L/APW + lo) method within the spin density functional theory. We used the Perdew–Burke–Ernzerhof (PBE) generalized gradient approximation (PBE-GGA) and the recently modified Becke–Johnson potential (mBJ-GGA) to generate the exchange–correlation potential. The optical constants as the dielectric function, refractive index and extinction coefficient were calculated and discussed in detail. Our compounds are identified as potential candidates for spintronic applications and high-performance electronic devices, due to their possible half-metallic character. The interband transitions responsible for the structures in the spectra are specified. It is shown that the Bi-p states and (Ca, Sr, Ba)-d states play the major role in optical transitions as initial and final states.