NANOSCALE IMAGING OF DOMAIN DYNAMICS AND RETENTION IN FERROELECTRIC THIN-FILMS

We report results on the direct observation of the microscopic origins of backswitching in ferroelectric thin films. The piezoelectric respo nse generated in the film by a biased atomic force microscope tip was used to obtain static and dynamic piezoelectric images of individual g rains in a polycrystalline material. We demonstrate that polarization reversal occurs under no external field (i.e., loss of remanent polari zation) via a dispersive continuous-time random walk process, identifi ed by a stretched exponential decay of the remanent polarization. (C) 1997 American Institute of Physics. [S0003-6951(97)00550-0].