Effects of background oxygen pressure on dielectric and ferroelectric properties of epitaxial (K0.44,Na0.52,Li0.04)(Nb0.84,Ta0.10,Sb0.06)O3 thin films on SrTiO3

Oxygen partial pressure (P-O2) in pulsed laser deposition significantly influences the composition, microstructure, and electrical properties of epitaxial misfit strain-relieved 450 nm < 001 > oriented epitaxial (K-0.44,Na-0.52,Li-0.04)(Nb-0.84,Ta-0.10,Sb-0.06)O-3 thin films on SrRuO3 coated SrTiO3. Films deposited at 400 mTorr exhibit high remnant and saturated polarization of 7.5 and 16.5 mu C/cm(2), respectively, which is similar to 100% increase over the ones grown at 100 mTorr. The dielectric constant linearly increases from 220 to 450 with increasing P-O2. The observed changes in surface morphology of the films and their properties are shown to be due to the suppression of volatile A-site cation loss.