Temperature dependences of the ice I hydrogen bond spectral shifts—I

Abstract

Abstract Changes in the infrared and far-infrared spectra of vitreous H2O ice Iv were observed at several temperatures between 92 and 210 K during the phase transformation to cubic ice Ic. The results of the phase transformation are reported as well for D2O ice I and HDO bearing ices. Between 120 ± 5 and 135 ± 5 K marked changes occurred in the structure of the spectrum as well as in the wavenumbers, half-widths and heights of the bands. Weak bands due to the stretching modes of weakly hydrogen bonded or oligomeric groups disappeared during this annealing, while modes associated with H2O stretching motions shifted to lower wavenumbers by 18–42 cm−1 and modes associated with hydrogen bond stretching and bending vibrations shifted to higher wavenumbers by 15–35 cm−1. The results indicate that the vitreous to cubic ice I phase transformation occurred between 120 and 135 K and required less than eighteen minutes to reach equilibrium at 135 K. The bands shifted reversibly in subsequent warming/cooling cycles with ΔνOH/ΔT = 0·20 cm−1 K−1 between 92 and 190 K.