Swift heavy ion induced modifications of optical and microstructural properties of silver–fullerene C60 nanocomposite

In this paper, we study the optical and microstructural properties of silver–fullerene C60 nanocomposite and their modifications induced by swift heavy ion irradiation. Silver nanoparticles embedded in fullerene C60 matrix were synthesized by co-deposition of silver and fullerene C60 by thermal evaporation. The nanocomposite thin films were irradiated by 120 MeV Ag ions at different fluences ranging from 1 × 1012 to 3 × 1013 ions/cm2. Optical absorption studies revealed that the surface plasmon resonance of Ag nanoparticles showed a blue shift of ∼49 nm with increasing ion fluence up to 3 × 1013 ions/cm2. Transmission electron microscopy and Rutherford backscattering spectroscopy were used to quantify particle size and metal atomic fraction in the nanocomposite film. Growth of Ag nanoparticles was observed with increasing ion fluence. Raman spectroscopy was used to understand the effect of heavy ion irradiation on fullerene matrix. The blue shift in plasmonic wavelength is explained by the transformation of fullerene C60 matrix into amorphous carbon.