Strain-induced single-domain growth of epitaxial SrRuO3 layers on SrTiO3: A high-temperature x-ray diffraction study

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 °C and remain tetragonal. The cause of this behavior is believed to be the compressive strain in the SrRuO3 layer due to the lattice mismatch with 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