Antiferrodistortive Structural Phase Transition in Compressively-Strained Epitaxial SrTiO3 Film Grown on (La, Sr)(Al, Ta)O-3 Substrate

(001)-epitaxial SrTiO3 films were grown on (La, Sr)(Al, Ta)O-3 substrates for investigating the impact of biaxial strain on the antiferrodistortive (AFD) structural phase transition in SrTiO3. The films were fully constrained by the substrates, which resulted in the large in-plane compressive strain of -0.9%. The AFD transition temperature estimated using temperature controlled x-ray diffraction and transmission electron microscope was over 150K higher than the theoretical prediction, but rather supported the experimental results reported on SrTiO3 films on LaAlO3 substrates.