International
Tables for
Crystallography
Volume H
Powder diffraction
Edited by C. J. Gilmore, J. A. Kaduk and H. Schenk

International Tables for Crystallography (2018). Vol. H, ch. 2.9, p. 197

Section 2.9.4. Complementary methods and future developments

W. van Beeka* and P. Pattisona,b

aSwiss–Norwegian Beamlines at ESRF, CS 40220, 38043 Grenoble CEDEX 9, France, and bLaboratory for Quantum Magnetism, Institute of Physics, Ecole Polytechnique Federale de Lausanne, CH-1015 Lausanne, Switzerland
Correspondence e-mail:  wouter@esrf.fr

2.9.4. Complementary methods and future developments

| top | pdf |

Standard crystallographic powder-diffraction methods can provide information about component phases and particle size, and can also be used to determine crystal structure, but the data quality required means that long-range crystalline order needs to be present. However, many real systems have amorphous components or demonstrate various degrees of disorder. In order to provide complementary information on the disordered components, alternative techniques are needed. In the early 1990s, Couves and co-workers started to combine XRD with XAFS in one setup in order to complement the XRD data (Couves et al., 1991[link]); they were quickly followed by Clausen and co-workers (Clausen et al., 1993[link]). Shortly afterwards, small-angle scattering (Dokter et al., 1994[link]) and vibrational spectroscopic techniques such as infrared and Raman were also added to complement the diffraction information (Newton & van Beek, 2010[link]). More recently, a very old technique (Tarasov & Warren, 1936[link]) based on the pair distribution function (PDF) has become immensely popular with the advent of high X-ray energies and efficient detectors (Chupas et al., 2003[link]). The PDF technique does not depend upon any assumptions about long-range crystalline order and can therefore be used to extract information on amorphous materials, defect structures and the structures of nanoparticles (see Chapter 5.7[link] ). It has the same huge variety of applications as traditional diffraction methods, and provides complementary information. Several of the in situ cells described above can also be used for combined techniques and PDF experiments at synchrotrons. One of the many reasons behind the rapid success of the PDF method is the availability of well developed software for data analysis (Juhás et al., 2013[link]) and modelling (Neder & Proffen, 2008[link]).

We have seen in some of the examples above that acquisition times are reaching down into the millisecond range and the quantity of data being delivered by modern systems is becoming increasingly difficult to analyse. There is progress in automated sequential and parallel parametric refinements with traditional data-analysis software. However, we believe new strategies are necessary in order to make better, more efficient use of modern detectors. There are efforts in this direction in automated chemometric methods (Burley et al., 2011[link]) stemming from spectroscopy. However, these algorithms are not always well adapted to analyse data derived from powder-diffraction measurements. Chernyshov et al. (2011[link]) have performed theor­etical and experimental work taking the interference nature of diffraction into account in their method, which is based on modulation. Nevertheless, improvements in data analysis are still trailing far behind experimental progress and much effort will be necessary in this area. Choe et al. (2015[link]) have even performed stroboscopic high-resolution powder diffraction on piezoelectric ceramics, detecting sub-millidegree shifts with microsecond time resolution.

In contrast to the pursuit of speed, the Diamond Light Source have decided to extend their powder-diffraction beamline and make it suitable for experiments lasting several months or even more, by moving slowly aging samples automatically into the measurement position at regular intervals (hours, days or even weeks) in a long-duration experiment (LDE) facility. Relevant applications are in batteries, fuel cells, crystallization, gas storage, mineral evolution, seasonal effects, thermal and electrical power cycling, and corrosion science.

In addition to the developments in instrumentation presented here, the availability of new radiation sources is opening up many interesting possibilities for studying chemical reactions. Not only are more, and better equipped, synchrotron beamlines becoming operational, but there are new facilities in planning or under construction that will dramatically change the way in which chemical processes can be investigated. New spallation sources and free-electron lasers (FELs) open up new possibilities in the time and space domains. In particular, FELs will facilitate the study of reactions on sub-picosecond timescales. Preliminary experiments using picosecond to nanosecond time resolution have already been carried out on synchrotron beamlines to investigate transient structural changes in organic powders (Techert et al., 2001[link]). It is evident that the huge increase in flux per pulse and the much shorter pulse length available from FELs will open up completely new dimensions in the field of in situ experiments.

References

Burley, J. C., O'Hare, D. & Williams, G. R. (2011). The application of statistical methodology to the analysis of time-resolved X-ray diffraction data. Anal. Methods, 3, 814–821.Google Scholar
Chernyshov, D., van Beek, W., Emerich, H., Milanesio, M., Urakawa, A., Viterbo, D., Palin, L. & Caliandro, R. (2011). Kinematic diffraction on a structure with periodically varying scattering function. Acta Cryst. A67, 327–335.Google Scholar
Choe, H., Gorfman, S., Hinterstein, M., Ziolkowski, M., Knapp, M., Heidbrink, S., Vogt, M., Bednarcik, J., Berghäuser, A., Ehrenberg, H. & Pietsch, U. (2015). Combining high time and angular resolutions: time-resolved X-ray powder diffraction using a multi-channel analyser detector. J. Appl. Cryst. 48, 970–974.Google Scholar
Chupas, P. J., Chapman, K. W., Kurtz, C., Hanson, J. C., Lee, P. L. & Grey, C. P. (2008). A versatile sample-environment cell for non-ambient X-ray scattering experiments. J. Appl. Cryst. 41, 822–824.Google Scholar
Chupas, P. J., Qiu, X., Hanson, J. C., Lee, P. L., Grey, C. P. & Billinge, S. J. L. (2003). Rapid-acquisition pair distribution function (RA-PDF) analysis. J. Appl. Cryst. 36, 1342–1347.Google Scholar
Clausen, B. S., Gråbaek, L., Steffensen, G., Hansen, P. L. & Topsøe, H. (1993). A combined QEXAFS/XRD method for on-line, in situ studies of catalysts: examples of dynamic measurements of Cu-based methanol catalysts. Catal. Lett. 20, 23–36.Google Scholar
Conterosito, E., Van Beek, W., Palin, L., Croce, G., Perioli, L., Viterbo, D., Gatti, G. & Milanesio, M. (2013). Development of a fast and clean intercalation method for organic molecules into layered double hydroxides. Cryst. Growth Des. 13, 1162–1169.Google Scholar
Couves, J. W., Thomas, J. M., Waller, D., Jones, R. H., Dent, A. J., Derbyshire, G. E. & Greaves, A. N. (1991). Nature (London), 354, 465–468.Google Scholar
Dokter, W. H., Beelen, T. P. M., van Garderen, H. F., van Santen, R. A., Bras, W., Derbyshire, G. E. & Mant, G. R. (1994). Simultaneous monitoring of amorphous and crystalline phases in silicalite precursor gels. An in situ hydrothermal and time-resolved small- and wide-angle X-ray scattering study. J. Appl. Cryst. 27, 901–906.Google Scholar
Jensen, T. R., Nielsen, T. K., Filinchuk, Y., Jørgensen, J.-E., Cerenius, Y., Gray, E. M. & Webb, C. J. (2010). Versatile in situ powder X-ray diffraction cells for solid-gas investigations. J. Appl. Cryst. 43, 1456–1463.Google Scholar
Juhás, P., Davis, T., Farrow, C. L. & Billinge, S. J. L. (2013). PDFgetX3: a rapid and highly automatable program for processing powder diffraction data into total scattering pair distribution functions. J. Appl. Cryst. 46, 560–566.Google Scholar
Linnow, K., Zeunert, A. & Steiger, M. (2006). Investigation of sodium sulfate phase transitions in a porous material using humidity- and temperature-controlled X-ray diffraction. Anal. Chem. 78, 4683–4689.Google Scholar
Morcrette, M., Chabre, Y., Vaughan, G., Amatucci, G., Leriche, J.-B., Patoux, S., Masquelier, C. & Tarascon, J.-M. (2002). In situ X-ray diffraction techniques as a powerful tool to study battery electrode materials. Electrochim. Acta, 47, 3137–3149.Google Scholar
Neder, R. B. & Proffen, T. (2008). Diffuse Scattering and Defect Structure Simulations. Oxford University Press.Google Scholar
Newton, M. A. & van Beek, W. (2010). Combining synchrotron-based X-ray techniques with vibrational spectroscopies for the in situ study of heterogeneous catalysts: a view from a bridge. Chem. Soc. Rev. 39, 4845–4863.Google Scholar
Rijssenbeek, J., Gao, Y., Zhong, Z., Croft, M., Jisrawi, N., Ignatov, A. & Tsakalakos, T. (2011). In situ X-ray diffraction of prototype sodium metal halide cells: time and space electrochemical profiling. J. Power Sources, 196, 2332–2339.Google Scholar
Robertson, K. & Bish, D. (2010). Determination of the crystal structure of magnesium perchlorate hydrates by X-ray powder diffraction and the charge-flipping method. Acta Cryst. B66, 579–584.Google Scholar
Tarasov, L. P. & Warren, B. E. (1936). X-ray diffraction study of liquid sodium. J. Chem. Phys. 4, 236–238.Google Scholar
Techert, S., Schotte, F. & Wulff, M. (2001). Picosecond X-ray diffraction probed transient structural changes in organic solids. Phys. Rev. Lett. 86, 2030–2033.Google Scholar
Tsakoumis, N. E., Voronov, A., Rønning, M., van Beek, W., Borg, Ø., Rytter, E. & Holmen, A. (2012). Fischer–Tropsch synthesis: an XAS/XRPD combined in situ study from catalyst activation to deactivation. J. Catal. 291, 138–148.Google Scholar
Walton, R. I. & O'Hare, D. (2000). Watching solids crystallise using in situ powder diffraction. Chem. Commun. pp. 2283–2291.Google Scholar








































to end of page
to top of page