Electronic, dielectric and optical properties of orthorhombic lanthanum gallate perovskite

Luo, B and Wang, X and Tian, E and Song, H and Li, G and Li, L (2017) Electronic, dielectric and optical properties of orthorhombic lanthanum gallate perovskite. Journal of Alloys and Compounds, 708. pp. 187-193. ISSN 0925-8388

Abstract

The electronic structure, dielectric and optical properties of orthorhombic LaGaO perovskite were investigated using first-principles calculations based on the density functional theory. Various density functional approximations were adopted, including GGA-PBEsol functional, meta-GGA-MBJ functional, HSE06 functional, and HSE (15%) functional (containing 15% “screened” Hartree-Fock exchange functional). After the full relaxation of LaGaO , the calculated lattice parameters were in great agreement with other experimental and theoretical results. The dielectric function, absorption coefficient, reflectivity, conductivity, refractive index, and electron energy-loss spectrum were calculated and discussed in detail. Results of band structure exhibited the indirect band gap of LaGaO with the value of 4.48 eV derived from HSE (15%) functional, which is in good agreement with the experimental value of 4.4eV. Strong hybridization between Ga atom and O atom, as well as the hybridization between La atom and O atom was observed from the density of states and electron charge density, revealing mixed bonding characteristic which is the essential for the ferroelectricity of orthorhombic LaGaO . 3 3 3 3