Ferroelectric nanodomain engineering at the −Z face of lithium niobate single crystals

Scanning force microscopy is used to investigate nanoscale ferroelectric domains engineering at the −Z surface of near-stoichiometric lithium niobate (SLN) single crystals. The SLN single crystal wafers fixed on the metal substrate are polished to about 3 μm thickness using the alumina powder and colloidal silica solutions. Dot patterns of the nanodomain structure are fabricated at the −Z surface of SLN wafers, which are switched by scanning these wafers with the external field exceeding the coercive field. The −Z polar surfaces in these patterns are preferentially etched by the mixture acid aqueous solution (HF:HNO3=1:1), a hexagonal shape of nanodomain patterns is clearly observed, which originates from the three-fold symmetry of the SLN crystal. It is considered that such nanodomain patterns can be effectively employed to create unique templates and devices.