Nature Communications, 16, 6536 (2025)

The antiferroelectricity of the historical oxide, PbZrO₃, remains heavily debated especially when it comes to low film thicknesses. Standard single crystal oxide substrates show a large lattice mismatch with PbZrO₃,leading to fast lattice relaxation during the growth and the formation of defects, such as dislocations. In this work, epitaxial thin films of PbZrO₃were grown on artificial substrates of LaLuO₃ by pulsed laser deposition, using a buffer electrode of SrPbO₃. This specific epitaxial stack introduces some tensile strain in the PbZrO₃ layers and stabilizes the orthorhombic Pbam phase from thicknesses of 200 nm down to 9nm. Capacitors based on such PbZrO₃ films display double hysteresis of polarization vs electric field down to thicknesses of 9 nm, and are corroborated by local STEM observations of the up-up-down-down antipolar pattern. These results emphasize the critical role of epitaxial strain in the stabilization of antiferroelectricity in ultrathin PbZrO₃.