Scanning nonlinear dielectric microscope for investigation of ferroelectric domains

This article describes a new purely electrical technique for imaging the state of remanent polarization of a ferroelectric material by measuring the microscopic point-to-point variation of its nonlinear dielectric constants. First, the theory for detecting polarization is described. Secondly, the technique for measuring the nonlinear dielectric response is described. Finally, using this new microscope, area scans are obtained of the polarization domains of lithium tantalate substrate with proton exchanged inversion layers, and of polarized and depolarized lead zirconate titanate ceramics.