Investigation on Mixed Alkali Bismuth-Borate glasses doped with Silver Nanoparticles

Abstract: The mixed alkali Bi-borate glasses with different concentrations of silver nitrate were produced by the melt- quenching method. The molar concentrations of silver were varied from 0.0 to 0.5mol% in steps of 0.1mol% and annealed at 300 degrees for two hours. The samples were characterized by powdered x-ray diffraction to conform the non- crystalline environment of the samples. The densities of the glasses were measured by the Archimedes principle. The glass sample were studies by the UV-Visible absorption spectroscopy. The formation of silver nanoparticles was indicated by the absorption band witnessed in the absorption spectra known as surface plasmon band. The plasmon band changes with the concentrations of silver doping. The silver nanoparticles in the glass environment were also confirmed by the transmission electron microscopy. The direct and indirect band gap valued were in the range 2.972-3.08eV and 1.786-2.782eV respectively. The Urbach energies and densities were found to change in similar way with the doping concentration but Urbach energy and the band gap energies were found to vary exactly in opposite manner. The plasmon band found was more sharp for less silver doping and with silver doping the band became more broad. The plasmon band formed due to the silver nanoparticles may be used to enhance the luminescence property of luminescent ions by making use of the plasmon resonance phenomenon.

Keywords: Silver Nanoparticles, Melt quenching, Surface Plasmon Resonance