Elongated Gold Nanoparticles Obtained by Ion Implantation in Silica: Characterization and T-Matrix Simulations

In this paper, Au nanoparticles obtained by ion implantation and a Subsequent thermal annealing have been elongated in a privileged direction by means of a postannealing 10 MeV Si ion irradiation. The modification and splitting of the surface plasmon resonance peak were determined by optical extinction spectroscopy, changing the polarization angle of the incident light. Moreover, the extinction spectra were accurately fitted with the T-matrix method, showing a good agreement with the results obtained by transmission electron microscopy, Rutherford backscattering spectrometry, and grazing-incidence small-angle X-ray scattering.