Relaxation Dynamics in Water Studied by Terahertz Time Domain Spectroscopy

Abstract

We measured terahertz time domain spectroscopy (THz-TDS) of H2O (light water) and D2O (heavy water) from 265 to 365 K. The results showed that terahertz absorption increases as the temperature increases in both kinds of water. We applied double Debye double Lorentz model to parameterize relaxation and vibration. We obtained high agreement with previous microwave and far-infrared results on slow relaxation and hydrogen bond bending and stretching and compared the isotope difference. Particularly we extract high precision fast relaxation parameter and its density-like temperature dependence.