Pulsed laser deposition of relaxor ferroelectric films

Heterostructures of perovskite relaxor ferroelectric (RFE) thin films onto La_0.5Sr_0.5CoO₃ bottom electrode layers were grown by pulsed laser deposition on MgO(100) crystal substrates. The films were highly oriented, with (h00) planes parallel to the substrate surface, and demonstrated good dielectric and ferroelectric quality at room temperature. The studies of the dielectric properties of the films over the frequency range of 20 Hz.... 100 kHz and over the temperature range of 0...350°C revealed relaxor type behavior in the films. A diffuse ferroelectric phase transition and a shift of the maximum dielectric permittivity towards higher temperatures with increasing frequency were observed. Interferometric measurements of piezoelectric response of the heterostructures at room temperature yielded piezoelectric coefficients in the range of 25...60 pm/V at 1 kHz, increasing up to 200...250 pm/V at 60 Hz. The obtained results look promising for micromechanical applications of RFE thin films.