Optically isotropy in scintillator host compounds M < inf > 2 < /inf > LaCl < inf > 5 < /inf > (M=Rb, and Cs): Ab-initio study

Abstract

Full potential linearized augmented plane wave method (FP-LAPW) has been used to calculate the electronic structure and optical properties of high light output scintillator host compounds M 2 LaCl 5 (M=Rb, and Cs) with in the Tran Blaha modified Becke Johnson (TB-mBJ) potential. These are wide band gap materials with the band gap of 4.75, and 4.72 eV for Rb 2 LaCl 5 , and Cs 2 LaCl 5 respectively. From the calculated optical properties of these compounds, we find these compounds to be optically isotropic, though they are structurally anisotropic, which is an important criteria for the ceramic scintillators.