Abnormal Domain Evolution in Lithium Niobate with Surface Layer Modified by Cu Ion Implantation

Abstract

Anomalies of domain structure evolution in congruent lithium niobate with surface layers modified by implantation of Cu ions were investigated. Formation of residual domains and growth of areas occupied by domain patterns with high density of charged domain walls were studied during cyclic polarization reversal. Growth of unusual three-rayed star domains was observed during polarization reversal in low external field much less than the threshold field for conventional congruent lithium niobate. The complicated geometry of these domains in the bulk was revealed using scanning laser confocal microscopy combined with Raman spectroscopy.

Keywords:

• Lithium niobate
• domain structure
• polarization reversal
• ion implantation
• surface modification

Acknowledgments

The research was made possible in part by RFBR (grants 08-02-12173-ofr, 08-02-99082-r-ofr, 10-02-96042-r-Ural-a, 10-02-00627-a), U.S. CRDF BRHE & FAE (PhD Award RNP 2.2.2.3.10017/Y4-P-05-11), by Federal Agency of Education (contract P870), by Federal Agency of Science and Innovation (contracts 02.740.11.0171 and 02.552.11.7069).