High Performance Pyroelectric Materials

Single crystals of triglycine sulfate (TGS), triglycine fluoberyllate (TGFB), deuterated triglycine fluoberyllate (D-TGFB), triglycine selenate (TGSe), mixed crystals of TGS and TGSe and 1-alanine doped TGS and TGFB were grown and characterized. Optimum crystal growth conditions were established. In particular, for D-TGFB which has the highest figure of merit, best crystal growth was obtained at a starting saturation temperature of 45 degrees, a seed rotation rate of 15 rpm, a pH of 3.6, a growth rate of 0.1 degrees per day for a volume of 10 liters, and a seed orientation in which the cleavage plane was parallel to the horizontal plane. Careful measurements were made of the pyroelectric coefficient and dielectric constant of a large number of samples of these homologs of TGS and consistent values were obtained. The superior figure of merit of D-TGFB was confirmed. The production of thin pyroelectric crystal targets by optical polishing and cup-etching was investigated. (Author)