High-resolution study of ferroelectric domain boundaries in lithium tantalate

Abstract

High-resolution (2·7 Å) images of 180° ferroelectric domain walls are reported for LiTaO₃. A crystallographic analysis shows that there are essentially six distinct possible structures for the domain walls. The actual structure is then determined by comparing experimental images with those predicted by computer simulation. It is established that polarity reversal simply involves Li-cation shifts of -1/6c. Both the images and the structural model show that the domain wall thickness in LiTaO₃ is virtually zero.