Orbital ordering induced ferroelectricity in SrCrO3

TL;DR

This study demonstrates that ultrathin films of SrCrO3 exhibit ferroelectricity induced by orbital ordering and lattice distortions, despite being metallic in bulk, suggesting a new pathway for multiferroic materials.

Contribution

It reveals that orbital ordering can induce ferroelectricity in ultrathin SrCrO3 films, a novel mechanism differing from traditional ferroelectric origins.

Findings

SrCrO3 ultrathin films become insulating due to orbital ordering.

Ferroelectric distortions in SrCrO3 produce polarizations comparable to conventional ferroelectrics.

Distinct mechanisms drive distortions in SrVO3 (Jahn-Teller) and SrCrO3 (ferroelectric).

Abstract

Using density functional theory calculations, ultrathin films of SrVO3(d1) and SrCrO3(d2) on SrTiO3 substrates have been studied as possible multiferroics. Although both are metallic in the bulk limit, they are found to be insulating as a result of orbital ordering driven by lattice distortions at the ultrathin limit. While the distortions in SrVO3 have a first-order Jahn-Teller origin, those in SrCrO3 are ferroelectric in nature. This route to ferroelectricity (FE) results in polarizations comparable with conventional ferroelectrics.