Scanning nonlinear dielectric microscopy with contact sensing mechanism for observation of nanometer sized ferroelectric domains

A new scanning nonlinear dielectric microscope with very high resolution for the observation of ferroelectric polarization was developed. This microscope has a newly developed contact sensing mechanism for detecting the exact contact point of a probe needle with respect to the surface of a specimen. This contact sensing mechanism enables us to use a probe needle with a very thin pointed end. Using the new microscope, domains in BaTiO₃ single crystal and in PbTiO₃ thin film were observed. By measuring the c-c domain wall of BaTiOs, the microscope was confirmed to have nanometer-order resolution.