Evolution of defect signatures at ferroelectric domain walls in Mg-doped LiNbO3

Guillaume F Nataf (1, 2) , Mael Guennou (2) , Alexander Hauβmann (3) , N Barrett (1) , Jens Kreisel (2, 4)

1 LENSIS - Laboratoire d'Etude des NanoStructures et Imagerie de Surface
2 Materials Research and Technology (MRT) Department, Luxembourg Institute of Science and Technology (LIST)
3 Institut für Angewandte Photophysik.
4 Physics and Materials Science Research Unit, University of Luxembourg

The domain structure of uniaxial ferroelectric lithium niobate single crystals is investigated using Raman spectroscopy mapping. The influence of doping with magnesium and poling at room temperature is studied by analysing frequency shifts at domain walls and their variations with dopant concentration and annealing conditions. It is shown that defects are stabilized at domain walls and that changes in the defect structures with Mg concentration can be probed by the shift of Raman modes. We show that the signatures of polar defects in the bulk and at the domain walls differ.

Keywords: defects; magnesium; Raman spectroscopy; single crystals; doping; lithium niobate; domain walls

Domains: Physics [physics]

Guillaume F Nataf, Mael Guennou, Alexander Hauβmann, N Barrett, Jens Kreisel. Evolution of defect signatures at ferroelectric domain walls in Mg-doped LiNbO3. physica status solidi (RRL) - Rapid Research Letters, 2016, 10, pp.222-226. ⟨10.1002/pssr.201510303⟩. ⟨cea-01349607⟩