IMF2017

The investigation of the domain evolution under local electric field produced by conductive tip of the scanning probe microscope on polar surface is one of the most informative. Recently the investigation by this method of the domain growth on non-polar surfaces allowed to reveal the detail information about forward domain growth. We provide the results of experimental study of the formation of quasi-regular structure of spike-like domains during scanning by grounded tip of scanning probe microscope without application of external electric field in the vicinity of the spike-like domain switched by rectangular field pulse. The effect was revealed at the non-polar X and Y cuts of congruent lithium niobate single crystals. The domains were visualized by piezoresponse force microscopy and the spatial distribution of the surface potential was measured by Kelvin probe force microscopy. The key role of the charges injected during pulse application was demonstrated. The multiplication of the domain structure period (doubling and tripling) has been observed. The formation of domain structure was attributed to: (1) action of the field created by localized injected charges, (2) screening of depolarization field by current in the external circuit, (3) electrostatic interaction of the isolated domains. We demonstrated non-uniformity and unipolarity of the charge injection and showed their influence on the parameters of domain structure. It was shown that during application of the switching pulse the injected charge propagated over the distance about tens of microns from the tip. The measured relaxation time of the injected charge is about several hours.