Room temperature ferroelectricity of tetragonally strained SrTiO3 thin films on single crystal Rh substrates

Epitaxial SrTiO3 thin films were deposited on single crystalline Rh substrates by pulsed laser deposition. The tetragonally stained structure of the SrTiO3 thin films with a c/a ratio of 1.04 was confirmed by x-ray diffraction experiments. The SrTiO3 thin films exhibited good ferroelectric properties with a high remanent polarization (2Pr) of 8 μC/cm2 and a canonical ferroelectric piezoresponse hysteresis loop at room temperature. We estimated a high activation electric field of about 6.4 MV/cm for domain wall creeping. This activation electric field is higher than that of typical ferroelectric materials such as PbTiO3.