In-situ x-ray diffraction study of the growth of highly strained epitaxial BaTiO_3 thin films

摘要

In-situ synchrotron x-ray diffraction was performed during the growth of BaTiO_3 thin films on SrTiO_3 substrates using both off-axis RF magnetron sputtering and pulsed laser deposition techniques. It was found that the films were ferroelectric during the growth process, and the presence or absence of a bottom SrRuO_3 electrode played an important role in the growth of the films. Pulsed laser deposited films on SrRuO_3 displayed an anomalously high tetragonality and unit volume, which may be connected to the previously predicted negative pressure phase of BaTiO_3.