Stability of nano-scale ferroelectric domains in a LiNbO_3 single crystal: The role of surface energy and polar molecule adsorption

摘要

The stability of nano-scale ferroelectric domains in a LiNbO_3 single crystal under varied atmospheric humidity levels was studied using piezoelectric force microscopy. Experimental results showed that the nano-scale domains fabricated by the tip field of the atomic force microscope changed as the environmental humidity changed; the c~- domains expanded or shrank with increases or decreases in the environmental humidity (that is, with the amount of adsorbed H_2O molecules on the domain surface), while the c~+ domains transformed in the opposite sense. The surface energy of the domains is responsible for these transformations.