Nuclear Spin—Lattice Relaxation in Ferroelectric Triglycine Sulfate

The temperature and frequency dependence of the 1H and 19F spin—lattice relaxation times in TGS, TGSe, and TGBe have been measured both in the ferroelectric and nonferroelectric phases, using a pulse technique. The results show that though a considerable slowing down of the proton motion occurs at the Curie points, the characteristic frequencies of internal motion are, in this range, still greater than the nuclear Larmor frequencies. The changes in the linewidth observed at certain orientations in the 1H and the additional splittings in the deuteron spectra on going to the ferroelectric phase are thus not due to a freezing in of internal motion but rather to a static rearrangement of the glycine units.