Structural characterization study of FeCo alloy nanoparticles in a highly porous aerogel silica matrix

J Chem Phys. 2007 Nov 28;127(20):204705. doi: 10.1063/1.2799995.

Abstract

A series of FeCo-SiO(2) nanocomposite aerogels having different FeCo loadings of 3, 5, and 8 wt % were prepared using a novel urea-assisted sol-gel route. The size of the nanoparticles, which was estimated using Scherrer analysis of the main peak of the x-ray diffraction pattern, varies from 3 to 8 nm. X-ray absorption fine structure (EXAFS) and x-ray absorption near edge structure (XANES) techniques at both Fe and Co K edges were used to investigate the structure of the FeCo nanoparticles. EXAFS and XANES show that FeCo nanoparticles have the typical bcc structure. Evidence of oxidation was observed in low FeCo content aerogels. Spatially resolved electron energy loss spectroscopy analysis suggests the formation of a passivation layer of predominantly iron oxide.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Alloys / chemistry*
  • Cobalt / chemistry*
  • Gels / chemistry
  • Iron / chemistry*
  • Metal Nanoparticles / chemistry*
  • Particle Size
  • Porosity
  • Silicon Dioxide / chemistry*
  • Spectrum Analysis / methods
  • Surface Properties
  • X-Ray Diffraction
  • X-Rays

Substances

  • Alloys
  • Gels
  • Cobalt
  • Silicon Dioxide
  • Iron