Electrical properties and phase transformations in antiferroelectric lead zirconate thin films

Field-induced phase transformations in antiferroelectric lead zirconate thin films were investigated at various temperatures. Films with (240) preferred orientations were prepared on Pt-coated Si substrates by a reactive magnetron co-sputtering method followed by rapid thermal annealing. Crystallization temperatures between 600 and 700°C resulted in square double hysteresis loops with large values of the maximum polarization (up to 70 μC/cm²). These very large values of induced polarization make such films attractive for energy storage applications. The phase transformations between the orthorhombic antiferroelectric phase and a rhombohedral ferroelectric phase, as well as ferroelectric-ferroelectric transitions were observed by studying the dielectric properties and the polarization-electric field hysteresis as a function of temperature. The behavior of the films is largely similar to that observed in single crystals, although the antiferroelectric-paraelectric phase transition temperature was increased by ~20°C. Work on the strain change accompanying the field-induced transformation will also be reported