Plasmonic Nickel Nanoantennas

J. Chen, P. Albella, Z. Pirzadeh, P. Alonso–Gonzales, F. Huth, S. Bonetti, V. Bonanni, J. Akermann, J. Nogues, P. Vavassori, A. Dmitriev, J. Aizpurua, and R. Hillenbrand

Small (Cover article) 7, p. 2341 (2011)
The fundamental optical properties of pure nickel nanostructures are studied by far-field extinction spectroscopy and optical near-field microscopy, providing direct experimental evidence of the existence of particle plasmon resonances predicted by theory. Experimental and calculated near-field maps allow for unambiguous identification of dipolar plasmon modes. By comparing calculated near-field and far-field spectra, dramatic shifts are found between the near-field and far-field plasmon resonances, which are much stronger than in gold nanoantennas. Based on a simple damped harmonic oscillator model to describe plasmonic resonances, it is possible to explain these shifts as due to plasmon damping.