Influence of composition gradients on heat induced initial domain structure in lithium tantalate

摘要

The initial domain structure was investigated in Z-cut plates of lithium tantalate crystal with various spatially nonuniform distributions of Li concentration along the polar axis formed by VTE annealing of different durations. The composition gradient resulted in formation of single domain layers near the polar surfaces. The single tail-to-tail charged domain wall formed in the center of the sample, where the composition gradient changed its sign. Nonuniform shape of the charged domain wall was attributed to the pyroelectric field. It was demonstrated that the shape of isolated domains changed with depth depending on the composition variation.