We have investigated the spin plasmonic properties of Magneto-plasmonic (MPl) hetero-nanostructuctures and the correlations between structural, chemical, optical and magnetic properties. MPl nanostructures are a new class of materials that exhibit simultaneously plasmonic and magnetic properties. Such combination of properties is obtained by combining nanoparticles or films of Au or Ag, that present surface plasmon resonances (SPR), with a magnetic component made of transition metals or metal oxides. This is a very promising class of multifunctional materials as the functionalities of the plasmonic and magnetic parts are very different. In addition to the combination of magnetism and optical properties, MPl materials exhibit new properties like SPR enhanced magneto-optical response, magnetic field modulated SPR and plasmon enhanced demagnetization. The full understanding of these properties is still matter of debate, but is mainly related to the interactions between the properties of the two components. As an example, magneto-optical dipolar emission of the magnetic part is enhanced by the electromagnetic field coming from the SPR, that in turn changes in frequency due to the dielectric properties of the magnetic part. Moreover, when the two materials share a large interface, chemical changes, crystalline modifications and electronic hybridizations could modify all the properties. The objective of our research is to investigate this type of effects. To this end we have investigated the structural, optical, chemical, magnetic and magneto-optical properties of MPl hetero-nanostructures composed of metallic Au and different Fe oxides. These hybrid systems were assembled in different architectures, like hetero-dimers, core-shell and flower-like structures, so as to have different contact surfaces. The hetero-nanostructures were investigated by combining several different techniques: Transmission Electron Microscopy, X-Ray diffraction, X-Ray Absorption Spectroscopy, X-Ray Magnetic Circular Dichroism Raman Microscopy, optical, magneto-optical and magnetic characterizations. We will show that the properties of the magnetic / plasmonic parts are really different in the hybrid systems. Moreover we will show that electronic hybridization can occur between the plasmonic and magnetic oxide parts. The effect depends on the chemical composition of the magnetic component. In particular, if the latter is Fe2+ rich, (presence of FeO), Au electrons are spin polarized.
|Titolo:||Correlation between spin polarization, magnetic properties and chemical state in magneto-plasmonic hetero-nano-structures|
LASCIALFARI, ALESSANDRO (Penultimo)
|Data di pubblicazione:||set-2011|
|Settore Scientifico Disciplinare:||Settore FIS/03 - Fisica della Materia|
Settore CHIM/02 - Chimica Fisica
|Citazione:||Correlation between spin polarization, magnetic properties and chemical state in magneto-plasmonic hetero-nano-structures / C. de Julián Fernández , F. Pineider, D. Cozzoli, M. Scavini, P. Gallinetto, G. Campo, C. Sangregorio, A. Lascialfari, P. Ghigna. ((Intervento presentato al 10. convegno Convegno Nazionale Materiali Nanofasici tenutosi a Bologna nel 2011.|
|Appare nelle tipologie:||14 - Intervento a convegno non pubblicato|