Nucleation and evaporation of domains due to electric field at room temperature in BaTiO3 single crystals

A study of nucleation and evaporation of 90∘ and 180∘ domains by external direct current (dc) electric field at room temperature in barium titanate single crystals has been carried out using reflecting microscope. It was observed that both the 90∘ and 180∘ domains were nucleated at some sites, while evaporated at some other sites of the crystal surface. The 90 ∘ domain follows the mechanism of micro-domain wall nucleation as well as the evaporation based on impurity dipoles, like reported for KNbO3. The mechanism of the 180∘ domain nucleation is not established yet. However, in both cases, nucleation and evaporation are operative simultaneously by the same electric field, which seems to be quite interesting and which can be attributed to the different critical lengths of the domains.