Abstract
Measurements have been made concerning the magnitude of the pyroelectric coefficient dPs/dT in LiNbO3 over the temperature range from 25° to 450°C. The pyroelectric coefficient was found to be −4×10−9 C/cm2/°C at 25°C. The spontaneous polarization was determined to be a decreasing function of temperature in the crystals measured which were pulled from the melt. Over the temperature range measured Ps was found to decrease by 3.7 μC/cm2. From these pyroelectric measurements and preliminary data on the temperature dependence of the nonlinear optical coefficient d33 in LiNbO3, for d33Ps, the magnitude of Ps at room temperature is estimated to be at least of the order of 50 μC/cm2.