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.