Neutron Powder Diffraction and Infrared Spectroscopy Study of the Ammonium Sulfate at Low Temperature

Our study reports the results of the temperature-dependent Fourier-transform infrared (FTIR) spectroscopy, a differential scanning calorimetry (DSC) and a neutron powder diffraction (NPD) on the ammonium sulfate at RT (paraelectric) and 30 K (ferroelectric). Heat capacity measurements with DSC show a clear anomaly at 223 K at the phase transition.Paraelectric-ferroelectric phase transition in ammonium sulfate associated with the hydrogen bonding presents an interesting and challenging research area. We determine the hydrogen bonds at different temperature and compare our NPD at RT with previously reported study¹. We assign FTIR spectral features of the sample and reveal the nature of their displacement patterns.
[1] E. O. Schlemper and W. C. Hamilton, J. Chem. Phys. 44, 4498 (1966).