Surface potential properties on near-stoichiometric LiNbO3 crystals with nanoscale domain-engineered structures

Abstract

We studied the surface potential properties of nanoscale domain-engineered structures on near-stoichiometric LiNbO3 crystals using Kelvin probe-based, electrostatic force microscopy. The surface potential image reflected in the domain structures could not be obtained clearly, because the spontaneous polarizations of the domains were neutralized by the in-air room temperature (298 K) screening charges. However, using heat-treatment in a vacuum, the surface potential image became clear, because of the decrease of the spontaneous polarizations and the protection of the screening charge adsorption. Furthermore, the surface potential contrast and polarity of the nanoscale domain-engineered structures could be changed repeatedly by changing the temperature between 298 and 393 K in the vacuum.