Differential calorimetry of lithium niobate single crystals

We conducted a series of calorimetric experiments with nominally pure lithium niobate single crystals congruent composition from different manufacturers and cuts, the samples were exposed to temperatures up 1100 ℃. For all samples, temperature feature is observed in range 800–900 °C, regardless their crystallographic orientation. The calculated activation energy about 150 kJ/mol indicates diffusion mechanism transformation, most likely associated high mobility niobium ions as well possibility formation oxygen vacancies crystal lattice niobate. In some cases, this technique can serve technological parameter for manufacture optical quality.