57Co Mossbauer emission study of LiNbO3, Fe:LiNbO3 and Mg:LiNbO3 in various thermochemical reduction states

Co-57 Mossbauer emission spectra of undoped and Fe or Mg melt-doped LiNbO3; single crystals show substantial amounts of the nucleogenic Fe3+ charge state (*Fe3+) which was generated as an after-effect of the electron-capture of Co-57(2+). The proportion of *Fe3+ is markedly dependent on the Mg content and on the stoichiometry of the sample. Electron trapping is described within the model of competing accepters. The capabilities of the model are investigated in defect structure analysis and charge trapping studies of LiNbO3.