First-principles calculations on electronic, chemical bonding and optical properties of tetragonal SrHfO3

Electronic, chemical bonding and optical properties of tetragonal SrHfO3 were investigated using the plane-wave ultrasoft pseudopotential technique based on the first-principles density functional theory (DFT). The optimized equilibrium lattice parameters of tetragonal SrHfO3 are in good agreement with experimental values. Band structure, densities of states (DOS), charge densities and molecular-orbital bonding structure of tetragonal SrHfO3 have been obtained. The band structure shows that tetragonal SrHfO3 has direct band gap. The DOS and charge densities indicate that bonding between Hf and O is mainly covalent due to Hf 5d and O 2p hybridization and that bonding between Sr and O is mainly ionic. The complex dielectric function, absorption coefficient, energy-loss spectrum, complex conductivity function and reflectivity of tetragonal SrHfO3 have been predicted. The imaginary and real parts of the calculated complex dielectric functions are consistent with the experimental observations.

Research highlights
► Electronic and chemical bonding properties of tetragonal SrHfO3 have been obtained using the first-principles calculations.
► Optical properties of tetragonal SrHfO3 have been predicted, the calculated complex dielectric functions are consistent with the experimental observations.
► Relations between electronic structure and optical properties of tetragonal SrHfO3 have been investigated using the theory of crystal-field and molecular-orbital bonding.