Transverse piezoelectric properties of epitaxial Pb(Yb 1/2Nb 1/2)O 3–PbTiO 3 (50/50) films

Abstract

The transverse piezoelectric properties of (1– x)Pb(Yb 1/2Nb 1/2)O 3– xPbTiO 3 (PYbN–PT, x=0.5) epitaxial films grown on (0 0 1)SrRuO 3/(0 0 1)LaAlO 3 (indices given for the pseudocubic unit cell) were investigated by the wafer flexure technique. PYbN–PT films and SrRuO 3 bottom electrodes were deposited by pulsed laser deposition. At a deposition pressure of 400 mTorr, (0 0 1) PYbN–PT epitaxial films with high phase purity and good crystalline quality were obtained for a wide range of deposition rates (40–100 nm/min) and temperatures (620–660°C). The remanent polarization of the film was as high as 30 μC/cm 2. The e 31 coefficient and the aging rate were strongly dependent on the poling direction. The maximum e 31 coefficient was −11.0 C/m 2. The minimum aging rate of the piezoelectric coefficients for the films was 2% per decade.