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

Abstract

Radiation defects induced by ion bombardment of multicomponent oxide glasses of seven compositions (phosphates, silicates, and borosilicates) implanted with Pb + ions at energy, E=150 keV, and three different doses were investigated by means of electron paramagnetic resonance (EPR). An anisotropic EPR spectrum attributed to molecular O 2 − ions was observed in the spectra of samples of all seven compositions. The number of O 2 − ions varies from 5×10 13 to 2×10 15cm −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 are 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. The observed spectra with g 1=2.0047; g 2=2.0030 and g 3=1.999 are attributed to CO 2 − ions. Based on data obtained for C +-implanted samples we show that a line with g∼ g e detected in spectra of many implanted glasses can be related to CO 2 − ions formed as a result of the interaction between displaced oxygen atoms and impurity carbon.