Cross-sectional observation of nanodomain dots formed in both congruent and stoichiometric LiTa O3 crystals

Cross-sectional shapes of polarization reversal nanodomain dots, formed in both congruent and stoichiometric LiTa O3 single-crystal recording media, were studied using scanning nonlinear dielectric microscopy. It was confirmed that the thickness of the domain wall of the nanodomain formed in stoichiometric LiTa O3 is much smaller than that in congruent LiTa O3. The variation in the domain wall thickness was evaluated as a function of sample thickness and depth position. It was confirmed that the domain wall thickness at the bottom of the sample was thinner than that at the top surface of the sample.