H-bond dynamics, Slater ice rules and Takagi group motion in a KDP-type deuteron glass

摘要

We have observed the dynamics of correlated hydrogen switching among the six Slater D_2PO_4 configurations induced by unpaired D_3PO_4 and DPO_4 Takagi group diffusion in a deuteron glass Rb_(0.5)(ND_4)_(0.5)D_2PO_4. The results obtained by two-dimensional (2D) ~(31)P exchange NMR prove the validity of the Slater-Takagi ice rules and allow for the direct determination of the correlation time for the unpaired Takagi group visits to a given D_2PO_4 group. They also explain the symmetry properties of these systems which are in apparent contradiction with the Slater rules.