Scanning nonlinear dielectric microscopy - a high resolution tool for observing ferroelectric domains and nano-domain engineering

A sub-nanometer resolution scanning nonlinear dielectric microscope (SNDM) was developed for the observation of ferroelectric polarization. We also demonstrate that the resolution of SNDM is higher than that of a conventional piezo-response imaging. Next, we report new SNDM technique detecting higher nonlinear dielectric constants epsilon(3333) and epsilon(33333). It is expected that higher order nonlinear dielectric imaging will provide higher lateral and depth resolution. Moreover, a new type of scanning nonlinear dielectric microscope probe, called the epsilon(311)-type probe, and a system to measure the ferroelectric polarization component parallel to the surface is developed. Finally, the formation of artificial small inverted domain is reported to demonstrate that SNDM system is very useful as a nano-domain engineering tool. The nano-size domain dots were successfully formed in LiTaO3 single crystal. This means that we can obtain a very high density ferroelectric data storage with the density above T-bits/inch(2) .