Paramagnetic species induced by ion implantation of Pb+ and C+ ions in oxide glasses

Radiation defects induced by ion bombardment of multicomponent oxide glasse s of seven compositions (phosphates, silicates, and borosilicates) implante d with Pb+ ions at energy, E = 150 keV, and three different doses were inve stigated by means of electron paramagnetic resonance (EPR). An anisotropic EPR spectrum attributed to molecular O-2(-) ions was observed in the spectr a of samples of all seven compositions. The number of O-2(-) ions varies fr om 5 x 10(13) to 2x10(15)cm(-2) depending on dose and glass composition. In phosphate samples an almost symmetric line (Z) with g = 1.9986 +/- 0.0005 was observed. The possible radiation defects responsible for this signal ar e discussed. This line is assigned to Pb ions. The EPR spectra of silicate and phosphate samples implanted with C+ ions at E = 80 keV were studied. Th e observed spectra with g(1) = 2.0047; g(2) = 2.0030 and g(3) = 1.999 are a ttributed to CO2- ions. Based on data obtained for C+-implanted samples we show that a line with g similar to g(e) detected in spectra of many implant ed glasses can be related to CO2- ions formed as a result of the interactio n between displaced oxygen atoms and impurity carbon. (C) 1998 Elsevier Sci ence B.V. All rights reserved.