Proton–deuteron mutual diffusion in a CsHSO4/CsDSO4 solid at 373K was

examined up to 3GPa by an infrared mapping measurement. Phases HPHT1 and

HPHT2 appeared at 1.5 and 2.3GPa, respectively, after heating. These phases were

found to be stable at room temperature, while phase IV, which appeared on

compression at room temperature, was metastable. The pressure dependence of the

proton–deuteron mutual diffusion coefficient was determined from the temporal

change in the deuteron distribution of the solid. The coefficient decreased from 7 x

10−16 to 1 x 10−16m2/s during the transition from phase II to HPHT1 at 1.5GPa, and

showed no significant change during the transition to phase HPHT2. These results suggested that in addition to the hydrogen bond length, other structural factors

might also have had an influence on the rate of diffusion.

Infrared Study of Proton–Deuteron Mutual Diffusion in a CsHSO4/CsDSO4 Solid

Under High Pressure. H.Yamawaki, H.Fujihisa, M.Sakashita, K.Honda: Physica

B, 2008, 403[17], 2643-8