The long-range reduction of CuO to Cu2O and Cu was observed upon bombarding polycrystals, or various planes ({110}, {020}) of CuO single crystals, with 16MeV N ions to a fluence of 1017/cm2. The infra-red absorption spectra revealed an increase in the number of hole [CuO4]5- and electronic [CuO4]7- centers. The highest density of electronic centers, and reduction, occurred near to the surfaces.

Centers of Charge Nonuniformity and Reduction of Copper Oxide During Irradiation with Nitrogen Ions. N.N.Loshkareva, J.P.Sukhorukov, S.V.Naumov, B.A.Gizhevskii, G.N.Tatarinova, T.A.Belykh: Fizika Tverdogo Tela, 1999, 41[9], 1564-7 (Physics of the Solid State, 1999, 41[9], 1433-6)