Polarisation dependent Raman study of single-crystal nickel oxide

The magnetic domain structure and Raman scattering have been studied in NiO single-crystals with three different (100), (110) and (111) orientations. Twin-domain structure was observed in NiO(100) and NiO(110) single-crystals using cross-polarized optical microscopy. We found that the ratio of the two-magnon (at 1500 cm⁻¹) to the two-phonon (2LO, at 1100 cm⁻¹) Raman bands intensity is sensitive in a particular way to the type of the twin-domain pattern.