The local atomic order and the valence state of Cu in Cu-implanted soda-lime glasses

Abstract

The local atomic order and the valence states of Cu ions ion-implanted into soda-lime glasses have been studied by X-ray absorption spectroscopy. The use of X-ray fluorescent yield and the total electron yield collection modes has allowed a separate investigation of the whole and the shallower part of the implanted region. The mean valence state of Cu depends on the implant dose, yielding Cu 2+ in the 1 × 10 16 Cu/cm 2 samples and a mixture of mainly Cu + and Cu 0 in 5 × 10 16 Cu/cm 2 samples. More reduced ions are present in the surface part of the implanted layer. In the ionic phase Cu has a well defined first coordination shell consisting of 3–4 O atoms at a distance between 0.186 ± 0.002 and 0.192 ± 0.002 nm. Metallic Cu crystalline clusters are found only in samples implanted with larger doses.