First-principles study of structural, elastic, electronic and optical properties of cubic perovskite LiMgF3 for novel applications

Abstract

Structural, elastic and optoelectronic properties of materials are important to identify their applications in technology. In the present paper LiMgF3 is investigated to obtain these properties using the highly accurate full-potential linearized augmented plane wave (FP-LAPW) method. The exchange correlation effects are included through the generalized gradient approximation (GGA) and modified Becke-Johnson (mBJ) exchange potential. The structural optimization of LiMgF3 is compared with previous results and is found to be in good agreement with those results. The predicted band structure shows an indirect (M-Γ) bandgap of 6.1 eV. The elastic properties such as elastic constants, anisotropy factor, shear modulus, Young’s modulus, Poisson’s ratio are calculated and based on these calculations it is found that this compound is elastically stable and brittle in nature. The contribution of different bands to the band structure is analyzed from the total and partial density of states curves. Optical properties like real and imaginary parts of dielectric function, refractive index, extinction coefficient, reflectivity, energy loss function, conductivity and absorption coefficient are presented. Based on the optical properties of the compound, it is predicted that LiMgF3 is suitable for optoelectronic devices.