Deuteron Magnetic Resonance in Deuterated Polycrystalline Ammonium Chloride and Sulfate

Publisher Website
Google Scholar
Abstract
Values of the quadrupole coupling constants |eQq|/h obtained at the temperature of liquid nitrogen for powdered specimens of deuterated ammonium sulfate and ammonium chloride have been found to be 161.9±0.3 and 175.7±0.7 kc/sec, respectively. Absolute values of the asymmetry parameter were estimated to be less than 0.2 from the powder spectra of the two salts. To obtain the deuteron quadrupole split spectrum of ND4Cl at liquid‐nitrogen temperature, it was found necessary to use very low rf field levels and also to irradiate the sample with a 60Co source to reduce the spin—lattice relaxation time. Second‐moment measurements were made on the single‐line spectrum of ND4Cl between room temperature and −83°C, from which an activation energy for rotational motion of the ND4+ ion was calculated to be 5.0±0.5 kcal/mole. At the temperature of the ferroelectric phase transition in (ND4)2SO4, a significant alteration of the electric field gradient was revealed by the change in the separation of the peaks in the five‐line deuteron magnetic resonance spectrum.