Point defects in ZX-cut Lithium niobate and Lithium tantalate and their influence on acousto-electric properties

The point defects in the spectra of photoluminescence of Lithium niobate (LN) and Lithium tantalate (LT) can be categorized as noble gases, heavy metals, and others. The distribution of charged defects (DCD) reveals peaks and valleys in a direction perpendicular to the z-axis, in both single crystals (SC) and periodically poled (PP) crystals. The distance between consecutive peaks and valleys equals the length of a ferroelectric domain in PPLT. The position of the ferroelectric domain wall with respect to point defects extrema is different in PPLT in comparison to PPLN. The DCD influences acousto-electric properties including electromechanical transduction (EMT) and electromechanical coupling coefficient (ECC), in a direction perpendicular to the z-axis. The results may be used to explain nonclassical nonlinearity in LN and LT crystals.The point defects in the spectra of photoluminescence of Lithium niobate (LN) and Lithium tantalate (LT) can be categorized as noble gases, heavy metals, and others. The distribution of charged defects (DCD) reveals peaks and valleys in a direction perpendicular to the z-axis, in both single crystals (SC) and periodically poled (PP) crystals. The distance between consecutive peaks and valleys equals the length of a ferroelectric domain in PPLT. The position of the ferroelectric domain wall with respect to point defects extrema is different in PPLT in comparison to PPLN. The DCD influences acousto-electric properties including electromechanical transduction (EMT) and electromechanical coupling coefficient (ECC), in a direction perpendicular to the z-axis. The results may be used to explain nonclassical nonlinearity in LN and LT crystals.