Silver nanocluster formation in ion-exchanged glasses by annealing, ion beam and laser beam irradiation: An EXAFS study G. Battaglin a , E. Cattaruzza a , F. Gonella a , R. Polloni a ,F.DÕAcapito b , S. Colonna c , G. Mattei d , C. Maurizio d , P. Mazzoldi d , S. Padovani d, * , C. Sada d , A. Quaranta e , A. Longo f a INFM, Dipartimento di Chimica Fisica, Universit  a di Venezia, Dorsoduro 2137, I-30123 Venezia, Italy b INFM, ESRF, GILDA-CRG, B.P. 220, F-38043 Grenoble, France c CNR-Istituto di Struttura della Materia, via Fosso del Cavaliere 100, I-00133 Roma, Italy d INFM, Dipartimento di Fisica, Universit  a di Padova, via Marzolo 8, I-35131 Padova, Italy e INFM, Dipartimento di Ingegneria dei Materiali, Universit  a di Trento, I-38050 Trento, Italy f ICTPN-CNR, via Ugo La Malfa 153, I-90146 Palermo, Italy Abstract ExtendedX-rayabsorptionfinestructureanalysisisusedtodeterminethesilverlocalenvironmentinsilicateglasses doped by the Ag-alkali ion-exchange process, followed by different treatments, namely, ion irradiation, thermal an- nealing in reducing atmosphere, laser irradiation. The obtained results indicate that metal nanocluster composites with different cluster structures may be formed with these multistep methodologies, pointing out the role of the preparation parameters in giving rise to different features. Lattice parameters and cluster diameter were determined by grazing incidence X-ray diffraction. Ó 2002 Elsevier Science B.V. All rights reserved. PACS: 61.46.+w; 81.05.Kf; 61.43.Fs Keywords: Nanoclusters; Glass composite; X-ray absorption spectroscopy 1. Introduction Novel preparation methods for metal nano- cluster composite glasses (MNCGs) use the ion- exchange process as the first step of combined methodologies, in which the metal ions introduced by the ion exchange are made aggregate by means of proper subsequent treatments such as irradia- tion with low-mass ion beams, heat-treatments in reducing atmosphere and pulsed laser irradiation [1–4].Inthisway,metalaggregationinnanometer- sized clusters is promoted, with several degrees of freedominthemultisteppreparationforeffectively defining the cluster structure and so the composite optical performances. Furthermore, nanoclusters * Corresponding author. Tel.: +39-049-827-7039; fax: +39- 049-827-7003. E-mail address: padovani@padova.infm.it (S. Padovani). 0168-583X/02/$ - see front matter Ó 2002 Elsevier Science B.V. All rights reserved. PII:S0168-583X(02)01717-2 Nuclear Instruments and Methods in Physics Research B 200 (2003) 185–190 www.elsevier.com/locate/nimb