Growth and characterization of ferroelectric LaTiO_3·5 thin films

Depending upon the oxygen content x, LaTiO3+x can be a semiconductor, a metal, or a ferroelectric at room temperature. Using a thin-film approach, it is in principle possible to adjust the oxygen content in the growth direction and thus tune the electronic properties within the same sample. We report here on a systematic study of the epitaxial growth of LaTiO3·5 films on SrTiO3 (110) substrates using molecular beam epitaxy. The epitaxial behaviour and the growth mechanism of these films have been investigated by means of X-ray diffraction, transmission electron microscopy, and in situ reflection high-energy electron diffraction analysis.