THE INFRARED ABSORPTION CHARACTERISTICS OF FERROELECTRIC TRIGLYCINE SULFATE

Author Institution: Bell Telephone Laboratories Inc.Infrared absorption spectra ($4000-625 cm^{-1}$) are reported for ferroelectric triglycine sulfate partially deuterated triglycine sulfate, and triglycine selenate. These and reflection and dichroic absorption data for variously oriented crystal sections of triglycine sulfate confirm what is presently known about its crystal structure. Notably, the spectra show that triglycine sulfate, unlike crystalline glycine, is not in the zwitterion form and that it contains three types of C---O group with at least two varieties of hydrogen bond. Although heating above the Curie temperature ($47^{\circ} C$) and exposure to x-rays are known to produce certain striking changes in the electrical properties of triglycine sulfate, the infrared absorption characteristics are found to be only very slightly affected."