Effect of the annealing temperature on the growth of the silver nanoparticles synthesized by physical route

Silver nanoparticles have attracted the attention due to their chemical stability, catalytic activity, localized surface plasma resonance, and high conductivity. Silver thin films with a thickness of ∼21 nm were deposited on corning glass substrate using radio frequency magnetron sputtering system. The deposited silver films were subsequently annealed to grow silver nanoparticles in the temperature range of 200℃ to 500℃ with the difference of 100℃ under a vacuum (Pressure ∼10⁻⁶ mbar) for fixed duration of 60 minutes. Composition and surface morphology of silver nanoparticles on the glass substrate were determined using field emission scanning electron microscope (FESEM) and atomic force microscopy (AFM) and energy dispersive spectroscopy (EDS). The results obtained from this study showed that by annealing at higher temperature, the flat silver thin films changed into rough silver thin films and further increment in temperature changed the silver thin films into silver nanoparticles. To study optical properties of Ag nanoparticles, the absorbance and diffuse reflectance spectra were also measured using UV–Vis–NIR spectroscopy.