Strain-coupled octahedral tilts and local polar displacements in superlattices

The ability to manipulate octahedral tilts and (anti-)ferroelectric polar displacements in perovksites is a path that opens the possibility of creating new materials with desirable optical, electric, and magnetic properties. We present a density functional investigation of the ability to control tilts and displacements in various short-period superlattices composed of absent-$A$-site perovskites WO$_3$ and ReO$_3$. We demonstrate that rotations and displacements of the $B$-cations in WO$_3$ are altered when layered with ReO$_3$. We also determine the thermodynamic stability of the superlattices, showing that ReO$_3$ fraction $> 50\%$ and with at least three ReO$_3$ layers are stable.