Speaker
Description
The electronic configurations of the two perovskite-type transition metal oxides SrTiO$_3$ and SrVO$_3$ differ by only one electron, yet they exhibit drastically different electronic properties. SrTiO$_3$ is a band insulator, while SrVO$_3$ is a correlated metal. The substitutionally doped alloy of these materials SrTi$_{1-x}$V$_x$O$_3$ has thus seen increased interest over the last decades. Measurements of the alloy have shown a metal insulator transition (MIT) over its composition range. Previous supercell calculations have shown that this MIT is the result of local electron correlation effects, also called Mott physics, between the $t_{2g}$ orbitals of the material and suggest that the MIT may also depend on site disorder. In order to further investigate the MIT we use the generalized quasichemical approximation (GQCA) together with density functional theory and dynamical mean field theory (DFT+DMFT). With this approach, we can model the disordered alloy at every composition.
We show that GQCA together with DFT+DMFT can successfully be used on highly correlated alloys. Furthermore, we model the MIT in SrTi$_{1-x}$V$_x$O$_3$ over the entire composition range using ab-initio methods.