Journal of Nanoparticle Research

, Volume 11, Issue 6, pp 1429–1439

Investigation of nanostructured Fe3O4 polypyrrole core-shell composites by X-ray absorbtion spectroscopy and X-ray diffraction using synchrotron radiation

  • Nicolae Aldea
  • Rodica Turcu
  • Alexandrina Nan
  • Izabella Craciunescu
  • Ovidiu Pana
  • Xie Yaning
  • Zhonghua Wu
  • Doina Bica
  • Ladislau Vekas
  • Florica Matei
Research Paper

DOI: 10.1007/s11051-008-9536-3

Cite this article as:
Aldea, N., Turcu, R., Nan, A. et al. J Nanopart Res (2009) 11: 1429. doi:10.1007/s11051-008-9536-3

Abstract

In this article, we focus on the structural peculiarities of nanosized Fe3O4 in the core-shell nanocomposites obtained by polymerization of conducting polypyrrole shell around Fe3O4 nanoparticles. The local structure of Fe atoms was determined from the Extended X-ray Absorption Fine Structure analysis using our own package computer programs. An X-ray diffraction method that is capable to determine average particle size, microstrains, as the particle size distribution of Fe3O4 nanoparticles is presented. The method is based on the Fourier analysis of a single X-ray diffraction profile using a new fitting method based on the generalized Fermi function facilities. The crystallites size obtained by X-ray diffraction spectra analysis was estimated between 3.2 and 10.3 nm. Significant changes in the first and the second Fe coordination shell in comparison with standard bulk were observed. The global and local structure of the nanosized Fe3O4 are correlated with the synthesis conditions of the core-shell polypyrrole nanocomposites.

Keywords

X-ray spectroscopySynchrotron radiationLocal and global structureMagnetite

Nomenclature

k

Wave vector

Aj(k)

Amplitude function

Ri

The radial distance

Ni

Number of atoms

Fi(k,r,π)

Backscattering amplitude

s

Scattering parameter

WF(k)

Apodization windows

h

Experimental X-ray line profile

g

Instrumental X-ray line profile

f

True sample function

H(L)

Fourier transform of h profile

G(L)

Fourier transform of g profile

F(L)

Fourier transform of true sample function

F(s)(L)

Fourier transform contribution about crystallite size and stocking fault probability

\( F^{(\epsilon)} (L) \)

Fourier transform contribution about microstrain of the lattice

Deff(hkl)

Effective crystallite size

\( \langle \epsilon^{2} \rangle_{hkl} \)

Microstrain of the lattice

A,a,b,c

Parameters of generalized Fermi function

ΔN

Uncertainties of atom numbers

ΔR

Uncertainties of coordination shell

ΔE0

Uncertainties of K edge position

FWHM

Full width at half maximum of true sample function

DSch

Crystallite size from Scherrer relation

Greek symbols

μ

Absorption coefficient

χ

EXAFS function

σ

Root means squares

λ

Mean free path function for inelastic scattering

Φ

Radial structure function

δh

Integral width of experimental profile

δf

Integral width of true sample function

Subscript

j

Coordination shell

Copyright information

© Springer Science+Business Media B.V. 2008

Authors and Affiliations

  • Nicolae Aldea
    • 1
  • Rodica Turcu
    • 1
  • Alexandrina Nan
    • 1
  • Izabella Craciunescu
    • 1
  • Ovidiu Pana
    • 1
  • Xie Yaning
    • 2
  • Zhonghua Wu
    • 2
  • Doina Bica
    • 3
  • Ladislau Vekas
    • 3
  • Florica Matei
    • 4
  1. 1.National Institute for Research and Development of Isotopic and Molecular TechnologiesCluj-NapocaRomania
  2. 2.Beijing Synchrotron Radiation Facilities of Beijing, Electron Positron ColliderNational LaboratoryBeijingPeople’s Republic of China
  3. 3.Romanian Academy, Timisoara BranchMagnetic Fluids LaboratoryTimisoaraRomania
  4. 4.Agriculture Sciences and Medicine Veterinary UniversityCluj-NapocaRomania