Observation of Hydrogen Localization Induced by Proton-beam Stress in TIH2PO4

Abstract

We have studied the microscopic structure of a proton-irradiated TIH2PO4 (TDP) sample under several temperature. The polycrystalline TDP sample was irradiated by a 1-MeV proton beam at a dose of 10(15)/cm(2). In general, solid materials exhibit a proton strong dipolar interaction and anisotropic chemical shifts that cause spectral line broadening and thereby hinder the observation of the crystal structure. Therefore, in order to determine the hydrogen displacements in the hydrogen bonds, one must eliminate dipolar interactions and anisotropic chemical shifts by using a high-resolution technique. Our H-1 combined rotation and multiple-pulse spectroscopy (CRAMPS) nuclear magnetic resonance (NMR) measurements indicate that the proton-irradiation stress causes a local strain change, implying the existence of a proton displacive component remaining on the structural modification of the O-H center dot center dot center dot O bonds.