Measuring ferroelectric polarization component parallel to the surface by scanning nonlinear dielectric microscopy

A scanning nonlinear dielectric microscope (SNDM) probe, called the ε₃₁₁-type probe, and a system to measure the ferroelectric polarization component parallel to the surface have been developed. This is achieved by measuring the ferroelectric material nonlinear dielectric constant ε₃₁₁ instead of ε₃₃₃, which is measured in conventional SNDM. Experimental results show that the probe can satisfactorily detect the direction of the polarization parallel to the surface. Moreover, we propose an advanced measurement technique using a rotating electric field, which can be applied to measure three-dimensional polarization vectors.