Optical, dielectric and mechanical properties of silver nanoparticle embedded calcium phosphate glass

Silver nanoparticles have been embedded in 50 mol% CaO-50 mol% P2O5 glass using melt quenching technique. The quenched glasses were heat treated at 550 °C for different durations between 10 and 50 h. The growth of silver nanoparticles in glass matrix appeared to be time dependent. FTIR spectra revealed that silver nanocluster formation had not affected the position of vibration bands of basic phosphate tetrahedral network. The Ag nanoparticle embedded glass matrix showed the red shift and broadening of the surface plasmon resonance (SPR) peak in the visible region with the increase in the duration of the heat treatment. Results showed the increase in size of the nanoparticles in glass matrix with heat treatment which was further confirmed using transmission electron microscopy and XRD. X-ray diffraction studies indicated the presence of Ag crystalline peaks along with amorphous structure on heat treatment at 550 °C for 50 h. The dielectric constant of these glasses increased as the duration of the heat treatment increased. Increase in both Vickers hardness and fracture toughness, and decrease in brittleness were observed which can be attributed to the increase in size of the nanoparticles in glass matrix.