Direct domain wall thickness measurement using scanning nonlinear dielectric microscopy

Using Scanning Nonlinear Dielectric Microscopy (SNDM) which has attained sub-nanometer resolution, we measured the linear dielectric constant of a-domains and c-domains in the (1,0,0) and (0,0,1) oriented PbZr0.2Ti0.8O3 thin film and confirmed that the dielectric constant of a-domain is higher than that of c-domain. Next, we observed 90degrees domain walls (a-c domain walls) and 180degrees domain walls (c-c domain walls) and we obtained the minimum value of 180degrees c-c domain wall thickness was 1.87 nm and 90degrees a-c domain wall was 2.52 nm.