Protons in neutron-irradiated and thermochemically reduced MgO crystals doped with lithium impurities

H- (hydride) ions have been observed in lithium-doped MgO crystals which have been neutron irradiated or thermochemically reduced (TCR). Infrared-absorption measurements have been used to identify the local modes of the H- ions in these crystals. The concentration of the H- ions in the neutron-irradiated crystals is found to be far less than that found in the TCR crystals. The thermal stability of H- and oxygen vacancies in both oxidizing and reducing atmospheres are investigated. The emergence of sharp structures due to OH- ions is attributed to the displacements of substitutional Li+ ions, leaving behind unperturbed OH- ions, via a mechanism of rapid radiation-induced diffusion during irradiation in a reactor. Results of neutron-irradiated MgO:Li, which had previously been oxidized at high temperature, are also presented