Growth of Self‐Organized Metal Nanostructures by Physical Methods

We report the synthesis of Ag and Au nanoparticles embedded in various matrices (silica, PET and a‐Si) by atom beam sputtering and thermal co‐evaporation. We have also synthesized Au nanorings using electron beam evaporation followed by subsequent annealing in inert atmosphere. UV‐Visible absorption, atomic force microscopy (AFM), X‐ray diffraction (XRD) and transmission electron microscopy (TEM) have been used for characterization of metal nanostructures. UV‐Visible spectra indicate the presence of metal nanoparticles by the surface plasmon resonance absorption peak at (∼400 nm for Ag and ∼520 nm for Au). XRD measurements reveal the average particle size that is confirmed by TEM and AFM. The work is in progress to use the prepared metal nanoparticles for (i) biomedical application such as detection of cancer cell (ii) detection of glucose (iii) surface enhanced Raman scattering (SERS) to enhance the characterization of biomolecules (iv) UV‐filter and (v) broad absorption band extending to IR region. The broad absorption of Ag‐polymer nanocomposites in infrared region shows the possibility of application of these nanocomposites in solar absorbers. Swift heavy ion (SHI) irradiation of the nanoparticles embedded in silica matrix shows the dissolution of nanoparticles. SHI irradiation can be used as a tool to tailor the optical properties of nanocomposites and also provides a fundamental understanding of the interactions of SHI with low dimensional materials.

Keywords:

• nanostructures, self-organization