Defect Complexes in Stoichiometric Lithium Niobate Crystals Prepared by Different Processes

Resumo

Using IR absorption spectroscopy in the stretching region of OH groups and Raman spectroscopy in the region of two-particle states of acoustic phonons, we have demonstrated that high-temperature top-seeded solution growth from a melt of congruent composition containing 6.0 wt % K₂O flux in Kristall-2 commercially available growth units makes it possible to obtain nearly stoichiometric LiNbO₃ crystals having approximately the same perfection of the proton sublattice as in stoichiometric crystals grown from a melt containing 58.6 mol % Li₂O, but considerably surpassing them in general optical and structural homogeneity.