Pressure Dependence of Protonic Diffusion Coefficient

The protonic diffusion coefficients measured for ice VII in a pressure range 

Protonic diffusion in ice has been investigated by a spectroscopic method. This method is based on the isotope effect on molecular vibrations. The mass difference between hydrogen and deuteron results in a frequency difference by a factor of V2 for the stretch mode. The peak positions are well separated in the spectra and hence their heights are converted to the H(D) concentrations with good accuracy. The diffusion process is monitored by measuring the reflection spectra of an H2O/ D2O ice bilayer, for which the equation of diffusion is described in analytical form. The H/D mutual diffusion coefficient measured at 400 K shows a monotonic decrease by two orders of magnitude as the pressure increases from 8 to 63 GPa. 

Petrenko, R. W. Whitworth, Physics of Ice, Oxford University Press, New York, 1999. 

Schuster, G. Zundel, C. Sabdorfy (Eds.), North-Holland, Amsterdam, p. 1425 (1976). 

Blicks, O. Dengel, N. Riehl, Phys. Kondens. MaterieA, 375 (1966). 

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