Effects of the domain wall conductivity on the domain formation under AFM-Tip voltages in ion-sliced LiNbO3 films

Abstract

The specified domain patterns were written by AFM-tip voltages in LiNbO3 films composing LNOI (LiNbO3-on-insulator). The domain wall conductivity (DWC) was estimated in the written patterns. This estimate was based on the effects of load resistors RL inserted between DWs and the ground, on the features of occurring domains. In this case, the domain formation is controlled by the ratio between RL and the DWs’ resistance RDW. Starting from the comparison of patterns appearing at different RL, the value of RDW in a specified pattern was estimated. The corresponding DWC is of σDW ≈ 10−3 (Ohm cm)−1 which exceeds the tabular bulk conductivity of LiNbO3 by no less than twelve orders of magnitude. A small DW inclination angle of (10−4)0 responsible for this DWC is not caused by any external action and characterizes the domain frontal growth under an AFM-tip voltage.