| AVS 54th International Symposium | |
| Plasmonics Topical Conference | Monday Sessions |
| Session PL-MoA |
| Session: | Plasmon Dynamics and Magnetoplasmonics |
| Presenter: | G. Armelles, Instituto de Microelectrónica de Madrid (IMM-CNM-CSIC), Spain |
| Authors: | G. Armelles, Instituto de Microelectrónica de Madrid (IMM-CNM-CSIC), Spain J.B. González-Diaz, IMM-CNM-CSIC, Spain A. Garcia-Martin, IMM-CNM-CSIC, Spain R. Asenjo, IMM-CNM-CSIC, Spain J.M. Garcia-Martin, IMM-CNM-CSIC, Spain A. Cebollada, IMM-CNM-CSIC, Spain B. Sepulveda, Chalmers University of Technology, Sweden Y. Alaverdyan, Chalmers University of Technology, Sweden M. Käll, Chalmers University of Technology, Sweden L.l. Balcells, ICMAB-CSIC, Spain |
| Correspondent: | Click to Email |
Noble metal-Ferromagnetic metal nanodisks exhibiting simultaneously localized surface plasmon resonances and magneto-optical (MO) activity were prepared from continuous Au/Co/Au films by colloidal lithography. Up to now, such phenomena have been only observed in continuous films made of Au/Co/Au trilayers. This system exhibits simultaneously well defined propagating surface plasmon resonaces and MO activity,1 and have been the basis to develop new high sensitive biosensors.2 However, a nanostructured system exhibiting localized surface plasmon resonances (LSPR) has two main advantages: i) the strong localization of the electromagnetic field around the nanostructures suggests a noticeable enhancement in the MO properties; ii) the spatial localization of electromagnetic fields associated with these resonances would make such a system a promising candidate for the development of high spatial specificity magneto-plasmonic sensing devices. Even though complex onion-like nanoparticles made of noble metals and ferromagnets that exhibit LSPR have been obtained using different chemical methods,3 no MO activity has been reported in any of them. In this work we show for the first time that such active nanostructures exhibiting optical and MO properties can actually be obtained. The nanodisks (60-110nm diameter) were prepared by colloidal lithography from Au/Co/Au films grown onto glass by sputtering. The absorption spectra of the samples exhibit a peak around 2 eV that can be associated to the LSPR of the nanodisks. As we increase the disk diameter the energy position of the peak shifts towards lower energies. The MO activity was determined measuring the Polar Kerr rotation and ellipticity spectra. These spectra present a well defined structure in the same energy region than that of the absorption peak. Moreover, an enhancement of the MO activity is also observed. The results will be explained with the help of theoretical simulations made with a scattering matrix formalism that takes into account the MO activity.
1 C.Herman et al. Phyts. Rev. Lett 73,3584(1994)
2 B. Sepúlveda et al. Oppt Lett.31,1085 (2006)
3 Z.Ban et al J. Mater. Chem 15, 4660 (2005); J. Zhang et al. J. Phys. Chem B 110, 7122 (2006); S. Mandal et al J. Mater. Chem 17 , 372 (2007); N. S. Sobal et al. Nano Letters 2, 621 (2002).