Structural and morphological properties of silver nanoparticles-phosphate glass composites

New types of composite materials belonging to the (100 - x) [50P(2)O(5) center dot 30CaO center dot 20Na2O]xAg(2)O glasses system with 0 <= x <= 0.25 are obtained. Their local structure is analyzed with the help of Raman and infrared spectroscopy and it was found that the glasses structure is built up from predominantly ionic phosphate units. UV - VIS absorption measurements performed on the samples reveal the existence of silver nanoparticles within the soda-calcium-phosphate glass matrix. The electronic absorption spectra and TEM pictures analyses indicate the presence of silver nanoparticles of almost spherical shapes and various sizes inside the glass matrix, depending on the Ag2O content. By using the experimental UV - VIS data and a theoretical approach important structural and morphological parameters, such as the radius of the silver nanospheres and the volume fraction of the spheres are determined for one of the investigated composites (x = 0.05 mol%). (C) 2006 Elsevier B.V. All rights reserved.