Perovskite phase stabilization in epitaxial Pb(Mg1/3Nb2/3)O-3-PbTiO3 filmsby deposition onto vicinal (001) SrTiO3 substrates

We report the perovskite phase stabilization of 0.67Pb(Mg1/3Nb2/3)O-3-0.33P bTiO(3) (PMN-PT) epitaxial thin films by deposition onto miscut substrates. Films were grown on (001) SrTiO3 substrates with miscut angles from 0 to 8 degrees toward the [100] direction using 90 degrees off-axis magnetron spu ttering. Films on high miscut substrates (>4 degrees) showed almost the pur e perovskite phase in both x-ray diffraction and transmission electron micr oscopy image, and were nearly stoichiometric. In contrast, films on exact ( 001) SrTiO3 contained a high volume fraction of pyrochlore phases with Pb d eficiency. Atomic force microscopy reveals that films on 8 degrees miscut s ubstrates have a much smoother surface morphology than those on exact (001) SrTiO3. Cross-sectional transmission electron microscopy images reveal tha t the pyrochlore phases nucleate on top of the perovskite phase, and that t he amount of the pyrochlore phases increase with film thickness. A film on an 8 degrees miscut substrate exhibits a polarization hysteresis loop with a remnent polarization of 20 muC/cm(2) at room temperature. (C) 2001 Americ an Institute of Physics.