Investigation of Periodic Domain Structures in LiNbO₃:Gd Single Crystals

Abstract

This work discusses the results of investigations of the growth of periodic domain structure in gadolinium-doped LiNbO₃ crystals using scanning electron and atomic-force microscopy (SEM and AFM). Comparative analysis of “head-to-head” and “tail-to-tail” domain walls allows us to reveal their difference in shape and physical properties. It was revealed by AFM in the lateral force mode and by SEM charging technique that the charging of the crystal surface near the “tail-to-tail” walls during electron bombardment occured slower and the same surface areas had altered elastic surface properties. It was supposed that observed morphological and physical peculiarities were caused by difference in gradients of Gd concentration and their spatial distribution near domain walls of different types.

Keywords:

• Lithium niobate
• periodic domain structures
• atomic-force microscopy
• scanning electron microscope
• lateral force mode
• surface charging
• domain wall

Acknowledgments

This work was partly supported by Russian Foundation for Basic Research (grant 09-02-00609a).