At the EPDIC-10 (European Powder Diffraction Conference) in Geneva in September 2006 a session dedicated to Total Scattering Analysis from powder diffraction data was organised. During this meeting the chairman of the IUCr Commission on Powder Diffraction, Prof. W. I. F. David (ISIS Facility, Rutherford Appleton Laboratory, UK) suggested one of the chairmen of the session to bring together people working in the with pair distribution function analysis to discuss developments and directions of the method. Besides, the need of sharing knowledge on the method among a wider community was evident, so that in the future this technique could be routinely exploited and become more generally available. So, the time seemed appropriate for a workshop to discuss developments and directions for X-ray and neutron diffraction studies on a large range of materials using Total Scattering Analysis.

A number of ESRF beam lines (e.g. ID11, ID15, ID27, ID31) are involved directly or in collaborations with users groups in the development and exploitation of the pair distribution function analysis method. Thus the location of the workshop at the ESRF seemed to be apt because it geographically converges the European X-ray PDF communities: this would foster co-operation between different groups and attract others to enter the field. In December 2006, the ESRF Experimental Division Management Board discussed and approved the proposition to organize this event at the ESRF in October 2007.

Here you can find various presentations of the speakers and a photo gallery containing some of the photos taken during the Poster and the Software demonstration session:

http://www.esrf.fr/events/conferences/PDFPowderDiffraction/

The participation of well over 100 people, the great majority being contributing rather than invited speakers, exceeded our original estimate. The meeting brought together a broad scientific community from about 15 different countries. The organising committee selected a limited number of invited speakers in order to give the users community the chance to present theirs works. Invited speakers were:

  • Simon J. L. Billinge                   Michigan State University, USA
  • Daniel T. Bowron                     ISIS Facility, UK
  • Stefan Brühne                           Frankfurt University, Germany
  • Peter J. Chupas                         Argonne National Laboratory, USA
  • Robert E. Dinnebier                 MPI Stuttgart, Germany
  • David A. Keen                          ISIS Facility, UK
  • Reinhard B. Neder                   Erlangen University, Germany
  • Thomas Proffen                        LANL Los Alamos, USA
  • Thomas Weber                          ETH-Zurich, Switzerland

 

The 24 oral contributions and posters covered breakthrough topics such as nanoporous materials, nanostructured bulk materials, high pressure and time-resolved studies, using the latest advances in PDF analysis. Some examples of research presented during the talks:

  1. The structure solution and refinement of nanostructures from atomic pair distribution function data: recently, it has been shown that ab-initio structure solution of nanostructured materials is feasible using diffraction data in combination with distance geometry methods and that precise, sub-Ångstrom resolution is experimentally available from the pair distribution function (PDF) [1, 2]. Unique ab-initio structural solution for C60 molecule was achieved from PDF data alone applying innovative algorithms [1-4].
  2. Accurate structural models for nanotubes [5] with applications of PDF analysis
  3. PDF studies of pressure-induced changes in zeolites
  4. Pressure induced amorphisation in ZrW2O8: structural analysis based on RMC modelling of neutron and X-ray total scattering [6].
  5. In recent work carried out by an ESRF user group [7], results from PDF analysis using powder diffraction data collected at an X-ray laboratory tube, ESRF and APS synchrotrons were compared. The results of the investigation clearly showed that PDFs from synchrotron radiation powder diffraction experiments have much higher Qmax and thus higher local structure content with respect to laboratory data. In particular, the data collected at the ESRF beam line ID31 have a better resolution in Q space, and hence are able to show clearer information in high r regions, which is needed for investigating larger scale “local” models.

 

Other topics of interest were:

  • Quasicrystals
  • Pharmaceutical compounds, pigments and Cd(S,Se) in ZrSiO4 (inclusion pigment)
  • CMR manganites
  • Negative thermal expansion materials
  • Catalysts: Silicates and Zeolites
  • Nano particles
  • Nano-transition-metal-oxides
  • Metallic alloys
  • Filtering of 2D powder diffraction data as a prerequisite for PDF analysis of samples in reaction and diamond anvil cells

In conclusion, the large and enthusiastic participation elicited by the workshop, the maturing state of the technique, and the particular relevance to the current objectives at the ESRF, particularly the investigation nano-scale structures, lead us to feel that PDF analysis will continue to be a growing field at ESRF. The necessity for the use of hard X-rays in order to achieve the necessary Q range means that the ESRF will remain the foremost facility for measuring PDF data in Europe. As the demand for these sorts of experiments is increasing, that position should be actively maintained by the further development of PDF related activities on the beam lines.

 

References:

[1] A. Wright, “Diffraction Studies of glass structure: the first 70 years”. Glass Phys. Chem. 24 148–179 (1998)

[2] T. Egami and S. J. L. Billinge, Underneath the Bragg peaks: structural analysis of complex materials. Pergamon Press Elsevier, Oxford England, 2003

[3] http://nirt.pa.msu.edu/

[4] Juhas et al., Nature 440 (2006) 655-658. Billinge et al., CPD IUCr Newsletter 24 (2000) 21

[5] V. Petkov, P. Y. Zavalij, S. Lutta, M. S. Whittingham, V. Parvanov, S. Shastri, Phys. Rev. B, 69 085410 (2004)

[6] D. A. Keen, A. L. Goodwin, M. G. Tucker, M. T. Dove,2 J. S. O. Evans, W. A. Crichton, and M. Brunelli Structural “Description of Pressure-Induced Amorphization in ZrW2O8”  Physical Review Letters 98, 225501 (2007)

[7] S. Brühne, E. Uhrig, K.-D. Luther, W. Assmus, M. Brunelli, A. Masadeh, S.J.L. Billinge Z. Kristallogr.(2005) 220 962–967.

 

More References:

S. J. L. Billinge and M. G. Kanatzidis, Chem. Commun., 749–760 (2004).

Zhang, H. Z., Gilbert, B., Huang, F. & Banfield, J. F. “Water-driven structure transformation in nanoparticles at room temperature”. Nature 424, 1025–1029 (2003).

Gilbert, B., Huang, F., Zhang, H., Waychunas, G. & Banfield, J. “Nanoparticles: Strained and stiff.” Science 305, 651–654 (2004).

Page, K. et al. “Direct observation of the structure of gold nanoparticles by total scattering powder neutron diffraction.” Chem. Phys. Lett. 393, 385–388 (2004).

T. Proffen, K. L. Page Z. Kristallogr. 219 (2004) 130–135

P.J.Chupas, X. Qiu, J. C. Hanson, P. L. Lee, C.P. Grey, S.J.L. Billinge, “Rapid-acquisition pair distribution function (RA-PDF) analysis”. J. Appl. Crystallogr. 36 (2003) 1342-1347.

Paglia et al. Chem. Mater. 18 (2006) 100

Kim et al., Phys. Rev. Lett., submitted (2006)

M. Scavini, M. Daldosso, M. Brunelli, C. Ferrero, C. Oliva, S. Cappelli, A. Lascialfari Europhysics Letters 76(3) (2006) 443–449

R L McGreevy J. Phys.: Condens. Matter 13 (2001) R877–R913

A. K. Soper, Physical Review B 72 (2005) 104204