Room-temperature electro-optic properties of strained SrTiO3 films grown on DyScO3

The electro-optic response of epitaxially strained SrTiO3 grown on bulk DyScO3 substrates is measured as a function of applied in-plane bias (both magnitude and direction) and light polarization. The effective electro-optic coefficients are bias-field dependent. Hysteresis is observed at room temperature, indicative of residual polarity, which is believed to be due to long-lived alignment of nanopolar regions possibly due to defects. A simple model incorporating non-180°-nanoscale domains can account for most of the experimental observations.