NMR spectra and translational diffusion of protons in crystals with hydrogen bonds

Investigation of proton transport in hydrogen-bond crystals at low temperatures is currently one of important problems in the semiconductor physics. With the use of the NMR spectra of wide-band-gap hydrogen-bond crystals grown in H$_2$O and D$_2$O solutions, we have succeeded in finding a direct proof of the presence of protons in the mobile phase, determined their activation energy in good agreement with the spectra of thermally stimulated depolarization currents and with the infrared spectra, and, as a result, clarified the mechanism of proton transport and tunneling.