Polarization Reversal in Crystals of Congruent Lithium Tantalate at Elevated Temperatures

Abstract

The polarization reversal has been studied in congruent single crystalline lithium tantalate, LiTaO₃, in temperature range from room temperature to 250°C. The fitting of the switching current data by modified Kolmogorov-Avrami formula allowed to reveal the main stages of the polarization reversal and to propose the original method of the threshold field measuring. The two times decrease of the threshold field was observed for 250°C. Essential change of the domain kinetics and shape of isolated domains at both polar surfaces was observed at temperatures above 200°C. The observed facts were attributed to effective bulk screening due to bulk conductivity increase.

Keywords:

• Domain structure
• domain kinetics
• lithium tantalate
• elevated temperature
• domain merging

Acknowledgments

The equipment of the Ural Center for Shared Use “Modern Nanotechnology”, Institute of Natural Sciences of the Ural Federal University has been used. The research was made possible in part by RFBR (grants 10-02-96042-r-Ural-а, 10-02-00627-а, 11-02-91066-CNRS-а), by Ministry of Education and Science (contract 16.552 11 7020), by OPTEC LLC, and by the financial support of young scientists of the Ural Federal University development program.