Insulator–metal phase transition in novel Sr2OsTiO6 double perovskite via doping - Computational FP study

Abstract

The structural, electronic, bonding, magnetic, optical and thermal properties of parent perovskite namely SrTiO3 (STO) and novel double perovskite namely Sr2OsTiO6 (SOTO) compounds are analyzed by using Full Potential (FP) - Linearized Augmented Plane Wave (LAPW) method through WIEN2K code. The optimized lattice parameter, bond length, bond angles, Fermi energy (EF), Density of States (DOS) at Fermi Level (FL), electronic specific heat coefficient are computed for the optimized STO and SOTO compounds. At ambient condition SrTiO3 is behaving as a semiconductor with a band gap 1.966 eV and via doping of SrOsO3 and SrTiO3, the resultant product of double perovskite phase namely Sr2OsTiO6 is shifted from the semiconductor state to a normal conductor state. Electron density plots, band structure plots and DOS are illustrated and compared for both STO and SOTO compounds. Diverse bonding and electronic band characteristics are noted and compared. Our band structure calculation results are reveal that the possibility of Electronic Topological Transition (ETT) in these compounds under the effect of doping. Since there is a predominant variation over the structural, electronic and magnetic properties of double perovskite even though not much variation over their mechanical properties. To illustrate the illumination properties of the compounds under study, the optical properties are also analyzed. Hence this study helps to lead the complete examination of suitable photovoltaic properties of STO and SOTO compounds.