Abstract

The synchrotron X-ray absorption technique was used to complement electron microscopy in the investigation of nanoparticles synthesized from the coreduction of iron acetylacetonate, Fe(acac)<inf>3</inf> and platinum acetylacetonate, Pt(acac)2. A much higher Pt composition than Fe leads to an extended X-ray absorption fine structure (EXAFS) spectrum for the sample that differs from that of fcc FePt nanoparticles. Most importantly, X-ray absorption near-edge structure (XANES) spectra clearly indicate the existence of α-Fe<inf>2</inf>O<inf>3</inf> and Pt metal. Since these monodisperse nanoparticles have a diameter of around 4nm and tend to self-assemble into hexagonal arrangements, they can be modeled as Pt-rich cores with an α-Fe<inf>2</inf>O<inf>3</inf> shell stabilized by organic surfactants. © 2012 K. Chokprasombat et al.