Atomic-resolution imaging of the polar (0001̄) surface of LiNbO 3 in aqueous solution by frequency modulation atomic force microscopy

Abstract

Atomic resolution images of the polar (0001̄) surface of lithium niobate (LiNbO 3) are achieved by frequency modulation atomic force microscopy operated at the solid-water interface. The measured data reveal a hexagonal surface unit cell. Its lattice constant corresponds to the bulk-truncated structure, suggesting that the high-temperature annealed surface does not reconstruct. Compared to the (0001̄) surface, high-resolution imaging on the oppositely charged (0001) surface is considerably more difficult to achieve. This finding is rationalized by density functional calculations that indicate a higher corrugation and softer bonds on the (0001̄) surface compared to the (0001) surface. © 2012 American Physical Society.