Combined measurements of thermostimulated processes in LiNbO3-surfaces

We measured thermally stimulated exoelectron emission and thermally stimulated luminescence of poled undoped LiNbO3 single crystals in air in the temperature region T = RT − 650 K. The emission appeared in pulses both upon heating and cooling in two temperature regions, T1 = 340–430 K and T2 = 560–620 K. Measurements of mass-spectra gave an evidence of Li2O and O desorption at temperatures as low as 32 3 K. Thermally stimulated desorption of Li2O and O in the temperature region T = RT − 800 K was found to peak at 380 K and 560 K. The discussion is based on the action of pyroelectric fields and on presence of microdomains with reversed polarity in the poled crystal.