Deuterium diffusion and magnetic resonance investigations in LiTaO3 single crystals.

The diffusion coefficients of deuterium in single crystals of ${\mathrm{LiTaO}}_{3}$ have been measured by monitoring the growth of ${\mathrm{OD}}^{\mathrm{\ensuremath{-}}}$ infrared-absorption bands in samples heated in flowing ${\mathrm{D}}_{2}$O vapor. At 950 K, the diffusion coefficient is 1.7\ifmmode\times\else\texttimes\fi{}${10}^{\mathrm{\ensuremath{-}}8}$ ${\mathrm{cm}}^{2}$/s for diffusion along the crystallographic c axis, and the activation energy is 1.5 eV. Electric-field-enhanced diffusion of deuterium was also demonstrated. Proton replacement and electron-nuclear double resonance experiments have shown that the structure previously reported in the electron paramagnetic resonance spectrum of a radiation-induced center in ${\mathrm{LiTaO}}_{3}$ is not due to a hyperfine interaction with protons.