Synthesis and Characterization of Nanocomposite Films with a Titania Glass Matrix by the Sol±gel Route

Films of thickness 3 mm containing nanosized metal particles of iron, nickel and copper respectively were grown on a Corning glass slide using a sol-gel technique. The particle sizes had values in the range 6.8 to 20.1 nm. Optical absorption characteristics of different specimens were studied over the wavelength range 230 to 830 nm. An absorption maximum was observed at wavelength varying from 270 to 300 nm depending on the nanocomposite system. The data were analysed on the basis of effective medium theories viz., Maxwell-Garnett (MG) and Bruggemann (BR) models respectively. MG model showed better agreement with experimental results than BR theory. The volume fraction as estimated from the least square fitting procedure was found to be in the range 2 to 3%. Copyright # 1999 John Wiley & Sons, Ltd.