  Temperature dependent structural phase transitions of SrRuO3 thin films
epitaxially grown on SrTiO3(001) single crystal substrates have been studied
using high-resolution x-ray diffraction. In contrast to bulk SrRuO3, coherently
strained epitaxial layers do not display cubic symmetry up to ~730 oC and
remain tetragonal. Such behavior is believed to be induced by compressive
strain between the SrRuO3 layer and SrTiO3 substrate due to lattice mismatch.
The tetragonal symmetry during growth explains the single domain growth on
miscut SrTiO3 substrates with step edges running along the [100] or [010]
direction.
