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.