New microscope for measuring the distribution of nonlinear dielectric properties

This paper describes a new technique for imaging the distribution of nonlinear dielectric constants of ferroelectric materials. This technique is based on the principle that the nonlinear (third-order) dielectric constants (third-rank tensor) are very sensitive to the state of the spontaneous polarization and the quality of the crystallization of materials, while the linear (second-order) dielectric constants (second-rank tensor) are insensitive to them. Applying this principle, a new microscope for measuring the distribution of nonlinear dielectric properties is developed. This new microscope is used to observe the distribution of the polarization of ferroelectric materials such as lead zirconate titanate (PZT) ceramic and piezoelectric polymer.