THE INFLUENCE OF PT AND SRTIO3 INTERLAYERS ON THE MICROSTRUCTURE OF PBTIO3 THIN-FILMS DEPOSITED BY LASER-ABLATION ON (001) MGO

We have used conventional and high-resolution transmission electron mi croscopy to investigate the microstructure of epitaxial, ferroelectric PbTiO3 films grown by pulsed laser ablation on (001) MgO single cryst als, and on MgO covered with epitaxial Pt or SrTiO3. Pronounced variat ions are found in the widths and lengths of a-axis-oriented domains in these films, although the volume fraction of a-axis-oriented material varies only weakly for the different types of samples. In addition, t he films deposited onto Pt-coated MgO have a larger grain size than th ose deposited onto bare MgO or SrTiO3/MgO. Possible reasons for the va riations in the distribution of a-axis-oriented material in these samp les include differences in the elastic properties and electrical condu ctivities of the different substrate combinations.