The impact of annealing and evaporation of LiNbO3 crystals on their surface composition

Auger electron spectroscopy and mass spectrometry have been used to investi gate the elemental composition of single-crystalline LiNbO3 surfaces subjec ted to annealing and evaporation in vacuum and to analyse the evaporation p roducts. We found three distinct temperature regimes, within which the surf ace composition of LiNbO3 undergoes different changes: outgassing (T = 300- 650 K); surface segregation of Li and O (T = 650-1150 K); and evaporation o f Li, O-2 and LiO (T greater than or equal to 1150 K). The evaporation of N b becomes noticeable only at temperatures close to the Curie temperature (1 483 K).