XANES and XMCD studies of FeRh and CoRh nanoparticles

Abstract

Element-selective magnetic properties of new core-shell bimetallic MRh (M=Fe or Co) nanoparticles (NPS) of 50/50 composition with either M@Rh or Rh@M core/shell order and an average diameter of ∼2 nm have been investigated by X-ray Absorption Spectroscopy (XANES) and X-Ray Magnetic Circular Dichroism (XMCD) technique. XANES spectra at the Rh L2,3 edges exhibit the same characteristic features for all systems having the Rh metal enriched shell. XMCD experiments at the same edges have shown that 4d states of Rh atoms acquire a magnetic moment as a result of hybridization with iron or cobalt 3d states. As expected the value of this induced moment depends on the 3d transition metal and on the core/shell chemical order in the nanoparticle. © 2010 IOP Publishing Ltd.