Simultaneous observation of nanometer size ferroelectric domains and surface morphology using scanning nonlinear dielectric microscopy

A new type of scanning nonlinear dielectric microscope (SNDM), with an additional function of simultaneous observation of surface morphology, has been developed. This was achieved by using an electrically conducting atomic force microscopy cantilever as a probe needle. Using this new SNDM, simultaneous measurements of several ferroelectric materials, such as periodically polarized LiNbO₃ and PZT thin films on SrTiO₃ substrates, were performed. Topographic and domain images, which were simultaneously taken from the same location of the materials, were successfully obtained. The result shows that nano-sized ferroelectric domain with the width of 1.5 nm for PZT thin film having a good correlation with a topographic image were observed. Moreover ferroelectric writing and reading are demonstrated using the SNDM system.