A method is proposed to control the aspect ratio (ε) of elongated nanoparticles obtained by ion implantation in a transparent matrix. The procedure was tested for Ag spheroids in silica and we could accurately change ε in the range from the maximum value obtained by the ion implantation (around 3.0 in this case) to 1.0 (spherical shape). The values of ε were determined in several steps from optical extinction spectroscopy measurements, by fitting the modification and splitting of the surface plasmon resonance peak, using the T-matrix method. In the initial (maximum deformation) and final (undeformed) states, transmission electron microscopy images were obtained, showing a good agreement with the T-matrix results in both cases.
© 2010 Optical Society of America
Original Manuscript: November 16, 2009
Revised Manuscript: December 23, 2009
Manuscript Accepted: January 11, 2010
Published: February 25, 2010
Vol. 5, Iss. 6 Virtual Journal for Biomedical Optics
V. Rodríguez-Iglesias, O. Peña-Rodríguez, H. G. Silva-Pereyra, L. Rodríguez-Fernández, J. C. Cheang-Wong, A. Crespo-Sosa, J. A. Reyes-Esqueda, and A. Oliver, "Tuning the aspect ratio of silver nanospheroids embedded in silica," Opt. Lett. 35, 703-705 (2010)