EXAFS STUDY ON METAL CLUSTER DOPED SILICA GLASS OBTAINED BY ION-IMPLANTATION PROCEDURES

Metal-doped glasses were prepared by double ion implantation (Ag+Cu an d Au+Cu) in silica glass. X-ray absorption spectroscopy was used to st udy the different oxidation states of the dopant metals and the possib le formation of metal or alloy clusters. We present an investigation o n co-implanted silica glass at the Cu K, Ag K and An L-III edges. The local atomic order around each dopant was determined. In particular, n o evidence of metal alloying was found. Cu is mainly bound to O atoms of the glass, Ag mainly forms pure metallic clusters and Au is present as small metallic particles and isolated atoms. (C) 1998 Elsevier Sci ence B.V. All rights reserved.