Irradiation induced dissolution of Cu and growth of Ag nanoclusters in Cu/Ag ion-exchanged soda-lime glass D. Manikandan a , S. Mohan a, * , P. Magudapathy b , K.G.M. Nair b a Raman School of Physics, Pondicherry University, Pondicherry 605 014, India b Materials Science Division, Indira Gandhi Center for Atomic Research, Kalpakkam 603 102, India Received 29 November 2001; received in revised form 17 September 2002 Abstract Complex metal nanoclusters of Cu/Ag are formed in a soda-lime glass matrix by sequential copper and silver ion- exchange followed by ion irradiation. Optical absorption measurements showed signature of copper clusters alone in the Cu/Ag ion-exchanged sample. Irradiation of the ion-exchanged sample with He þ ions of energy 100 keV of different fluences resulted in the growth of the silver clusters with, the optical absorption spectrum exhibiting two peaks cor- responding to the surface plasmon resonance of copper and silver in the same matrix. It was found that with increase in fluence the silver clusters begin to grow while the already formed copper clusters segregate, which can be visualized from the absorption spectra, where the copper band disappears while the silver band grows with the increase in dose. Vacuum annealing of the Cu/Ag ion-exchanged samples resulted in complete disappearance of copper clusters while the silver clusters grew till they attained saturation. The glancing incidence X-ray diffraction study of the Cu/Ag ion-exchanged and irradiated sample showed silver peaks alone with no information of alloying between the two species. Ó 2002 Elsevier Science B.V. All rights reserved. Keywords: Cu/Ag; Ion-exchange; Ion irradiation; GIXRD; Soda-lime glass 1. Introduction Dielectric with embedded metal or semicon- ductor nanoclusters have attracted a great deal of attention due to their potential application in the field of all optical switching devices [1]. Single el- ement metal nanocluster composite glasses have been formed by ion implantation or by ion-ex- change followed by ion irradiation. The dielectric confinement effects of these non-interacting nanoscale materials increase the optical absorption at surface plasmon resonance (SPR) frequency [2– 4]. The electronic structure of these nanoclusters affecting the optical properties can be altered by sequential ion implantation thus forming multi- component nanoclusters. Complex nanoclusters of Ag/Cu, In/Cu, In/Ag and Ag/Sb were formed in silica by sequential ion implantation [5–9], which resulted in the tailoring the physical properties of the nanostructures formed. In this paper we report the formation of Cu/Ag nanoclusters in soda-lime glass by sequential ion-exchange and their optical properties when subjected to He þ ion irradiation and vacuum annealing. Nuclear Instruments and Methods in Physics Research B 198 (2002) 73–76 www.elsevier.com/locate/nimb * Corresponding author. Tel.: +91-413-655991x402 (Off), +91-413-655235 (Res); fax: +91-413-655265/211/255. E-mail address: s_mohan@lycos.com (S. Mohan). 0168-583X/02/$ - see front matter Ó 2002 Elsevier Science B.V. All rights reserved. PII:S0168-583X(02)01518-5