AVS 54th International Symposium | |
Plasmonics Topical Conference | Monday Sessions |
Session PL-MoA |
Session: | Plasmon Dynamics and Magnetoplasmonics |
Presenter: | J.C. Owrutsky, Naval Research Laboratory |
Authors: | J.C. Owrutsky, Naval Research Laboratory A.D. Berry, Naval Research Laboratory G.M. Sando, Malvern Instruments |
Correspondent: | Click to Email |
Steady state and ultrafast transient absorption studies have been carried out for gold, nickel, and palladium high-aspect ratio nanorods. For each metal, nanorods were fabricated by electrochemical deposition into ~6 µm thick polycarbonate templates using two nominal pore diameters (10 nm and 30 nm, resulting in nanorod diameters of about 40 and 60 nm, respectively). Static spectra of the nanorods for each metal reveal a mid infrared longitudinal surface plasmon resonance (SPR) band as well as a transverse SPR band in the visible for the gold and larger diameter nickel and palladium nanorods. This demonstrates that high aspect ratio nanorods of transition metals have mid infrared SPR bands. Time resolved studies were performed on the gold and nickel nanorods with subpicosecond resolution, 400 nm excitation, and a wide range of probe wavelengths from the visible to the mid-IR as well as using infrared excitation (near 2000 cm-1) and probing at 800 nm. The dynamics observed for both diameters of gold and nickel nanorods include transients due to electron - phonon coupling and impulsively excited coherent acoustic breathing mode oscillations, which are similar to those previously reported for spherical and smaller rod-shaped gold nanoparticles. The results demonstrate that the dynamics of high aspect ratio metal nanorods resemble those for smaller nanoparticles.