Activation energy of small polarons and conductivity in LiNbO 3 and LiTaO 3 crystals

Eliminating pyroelectric and other disturbances, with the aid of the curves of bulk and surface current versus temperature, the conductivity character of LiNbO 3 (LN) and LiTaO 3 (LT) is studied at different temperatures. The activation energy is obtained, which is needed for bound small polarons in LN and LT crystals to jump across their potential barrier to give rise to hopping conduction.