Orientation-dependent piezoelectric properties in lead-free epitaxial 0.5BaZr0.2Ti0.8O3-0.5Ba0.7Ca0.3TiO3 thin films

Orientation-engineered 0.5BaZr(0.2)Ti(0.8)O(3)-0.5Ba(0.7)Ca(0.3)TiO(3) (BZT-BCT) thin films were deposited on La0.7Sr0.3MnO3-coated SrTiO3 single-crystalline (001), (110), and (111) substrates by off-axis radio-frequency magnetron sputtering. X-ray diffraction confirmed a highly epitaxial growth of all the as-deposited films. It is believed the strong orientation dependence of ferroelectric and piezoelectric properties on the films is attributed to the relative alignment of crystallites and spontaneous polarization vector. The optimal ferroelectric response lies in the [001] direction, whereas a comparatively large effective piezoelectric coefficient d(33,eff) of 100.1+/-5 pm/V was attained in [111] BZT-BCT thin film, suggesting its potential application for high-performance lead-free piezoelectric devices. (C) 2013 AIP Publishing LLC.