Electronic, bonding and elastic properties of the ordered SrTi${}_{1-x}$Zr${}_x$O${}_3$ alloys. A first principles study

By means of first-principles calculations based on the density functional theory (DFT), we have investigated the structural, elastic, electronic, and bonding properties of three SrTi${}_{1-x}$Zr${}_x$O${}_3$ alloys. The study shows that the substitution of Ti ion by the Zr one can also be undertaken by a tetragonal structure. However, due to the similar ionic radii between substitute cation, the choice of this super-cell leads to a weak change in both structural and dynamical properties and behave similarly even under different applied strains. Electronic as well as bonding properties are more affected by the substitution due to the rearrangement of the atomic orbitals. The calculations of band gaps depict a possible use of the investigated alloys in many UV device applications. Additionally, we will show that deep insight of bonding properties depicts some difference in ionicity degree between alloys. This trend is due essentially to the change in electron valence resulted in a weak variation of energetic orbitals.