Metallic nanoparticles detected by infrared spectroscopy

¹  Laboratoire de Chimie Physique - Bât. 201P2, Université de Paris Sud, 91405 Orsay cedex, France
²  Laboratoire de Métallurgie-Physique, Université de Poitiers - Bât. SP2MI, BP 30179, 86962 Futuroscope-Chasseneuil Cedex, France
³  Instituto de Ciencia de Materiales de Madrid - Cantoblanco, 28049 Madrid, Spain
⁴  Centre de Recherches sur les Matériaux à Haute Température - 1D avenue de la recherche scientifique, 45071Orléans Cedex 2, France

Corresponding author: agnes.traverse@u-psud.fr

Received: 1 August 2007
Accepted: 5 December 2007

Abstract

Small Ni, Cu, Fe, Ag, Pt, Au nanoparticles with average diameters in the nanometer range have been studied by infrared spectroscopy. The Ni, Cu, Fe, Ag, Au nanoparticles were embedded in transparent matrices, AlN or Si₃N₄, or deposited on Si₃N₄ in the case of Pt. They were previously characterized by several techniques such as X-ray absorption spectroscopy, grazing incidence small-angle X-ray scattering or transmission electron microscopy. Infrared absorption depending on the metal is detected in the 60 meV to 140 meV energy range. It is interpreted as due to low-energy collective electron excitations related to the 2D confinement occurring at the metal-matrix interface.