Rotating-frame nuclear magnetic resonance study of the distinct dynamics of hydrogen donors in ZnO

摘要

The rotating-frame spin-lattice relaxation of two types of the hydrogen donors was well distinguished in the ~1H nuclear magnetic resonance measurements in a sol-gel prepared ZnO system, providing a unique opportunity to study the distinct proton dynamics. Our study indicates interconversion of the interstitial H (H,). The population of the mobile H_i showed decrease above ～370 K, apparently being trapping into the oxygen vacancies resulting in the more stable oxygen-substitutional H (Ho). The activation barrier for migration of H_i and the binding energy of H_O were found to be 0.27 eV and 0.51 eV, respectively.