Tertiary pyroelectric effect on thick ferroelectric crystal plates with partially uniform heating

Based on the state equation and thermal shear stress. the tertiary pyroelectric effect of thick ferroelectric crystal plates with partially uniform heating is discussed. The polarizations of 2, 3m and 4mm point group crystals produced by the tertiary pyroelectric effect are derived. The results show that at the upper and lower surface separation of heated and nonheated region, electric charges will be induced with density proportional to the temperature gradient at the separation and to the thickness of the plate. Calculations concerning LiNbO3 crystal are in accord with experiments.