Local probing of the interaction between intrinsic defects and ferroelectric domain walls in lithium niobate

Abstract

We demonstrate the capability of confocal Raman spectroscopy to characterize nanoscale interactions of defects with ferroelectric domain walls by identifying defect-related frequency shifts in congruent lithium niobate. These shifts resemble those observed for an external field applied anti-parallel to the ferroelectric axis, suggesting a small reduction of the electric polarization. Density functional theory calculations suggest that this reduction results from a change in the intrinsic defect cluster structure and polarization at the domain wall. (C) 2013 American Institute of Physics. [http://dx.doi.org/10.1063/1.4789779]