Eur. Phys. J. B 34, 25-31 (2003)
https://doi.org/10.1140/epjb/e2003-00192-5

An ellipsometric investigation of Ag/SiO₂ nanocomposite thin films

¹ Department of Materials Science, Indian Association for the Cultivation of Science, Calcutta 700 032, India
² Inter University Consortium for DAE Facilities, Sector III, Block LB/8, Bidhan Nagar, Calcutta 700 098, India
³ Spectroscopy Division, Bhabha Atomic Research Centre, Mumbai 400 085, India

Corresponding author: ^a msakp@iacs.res.in

Received: 6 December 2002
Revised: 3 April 2003
Published online: 23 July 2003

Abstract

Dielectric properties of silver/SiO₂ nanocomposite thin films grown by high-pressure d.c. sputtering technique were studied by spectroscopic ellipsometry (300–800 nm). The dielectric behavior of the nanocomposite thin films largely depended on the particle size, its number density and the surrounding environments. The films showed semiconductor-like behavior up to a critical particle size and concentration, beyond which the films exhibited the typical surface plasmon resonance characteristics in their optical properties. The refractive index was also found to have a strong dependence on the particle size and its dispersion in the matrix. The results were found to be consistent with those obtained from UV-VIS optical absorbance data. Bruggeman effective medium theory was used to explain the experimental results.