In 1993 Kuz’minov and Osiko pointed out the ‘disturbance�?of stoichiometry in LN crystals is mainly a result of the deficiency of oxygen in Nb2O5, used for a Uncooked material initial soften (Czochralski process) [186]. Appropriately, according to its production technological know-how, niobium pentoxide can undertake a wide range of compositi