First-principles calculations of epitaxially strained PbZrO$_3$: Coexistence of antiferroelectricity and ferroelectricity

The antiferroelectric (AFE) - ferroelectric (FE) field-induced transition has important applications in energy-storage capacitors and piezoelectric devices. PbZrO$_3$ is the best known AFE material. Polycrystalline and single crystals PbZrO$_3$ posses a stable AFE ground state below 505 K. In thin films, experimental results show coexistence of antiferroelectricity and ferroelectricity at room and low temperatures. First-principles calculations of epitaxially strained PbZrO$_3$ are carried out to give further evidence of this coexistence and to study the polarization switching path. The space groups of the AFE and FE structures are identified together with their important structural and electrical features.