Thickness-driven antiferroelectric-to-ferroelectric phase transition of thin $PbZrO3$ layers in epitaxial $PbZrO3∕Pb(Zr0.8Ti0.2)O3$ multilayers

Epitaxial antiferroelectric/ferroelectric $PbZrO3∕PbZr0.8Ti0.2O3$ multilayers were grown on $SrRuO3$-electroded $SrTiO3(100)$ substrates by pulsed laser deposition. Polarization-field and switching current-voltage curves show a mixed antiferroelectric-ferroelectric behavior of the multilayers with an individual layer thickness above $10nm$⁠, whereas below $10nm$ the multilayers show only ferroelectric behavior. Clearly the $PbZrO3$ layers thinner than $10nm$ experienced a transition into the ferroelectric state. X-ray diffraction reciprocal space mapping showed a corresponding orthorhombic-to-rhombohedral transition of the $PbZrO3$ layers. The observations are discussed in terms of the influence of strain.