Phase composition of Z-cut protonated LiNbO3: a Raman study

In this paper both micro- and waveguide Raman scattering in the 30-800 cml Frequency region were used to investigate the number and type of the phases existing in proton exchanged Z-cut LiNbO3. As-exchanged and annealed sampl es have been measured with various proton concentrations providing the pres ence of all phases supposed to exist in crystalline protonated LiNbO3. The analysis of the Raman data implies the existence of alpha, kappa (1) (kappa (2)), beta (1), beta (2) (beta (3)) and beta (4)-phases. No sandwich-like structure (with maybe the exception of beta (4)/beta (3)(beta (2)) configur ation) was observed. Quantitative relations between the characteristics of some phonons and the proton concentration were established. (C) 2001 Elsevi er Science B.V. All rights reserved.