Rietveld Refinement, Rietveld Analysis, Rietveld Technique, Rietveld Calculation,
Rietveld Quantitative Phase Analysis
"Discovery consists of seeing what everybody has seen and thinking what nobody has thought."
Albert von Szent-Györgyi (Nobel prize-winner in 1937)
essential to our
technological society: semiconductors in the electronic industry,
zeolites as catalysts in the petrochemical industry, ceramics in
engineering, and, possibly in the future, high-temperature
superconductors in electrical engineering.....
In order to understand the properties of these materials and to improve them, the atomic structure has to be known. An effective way to do this is by means of diffraction techniques using neutrons from nuclear reactors and particle accelerators or X-rays from X-ray tubes and synchrotrons. The single crystal diffraction technique, using relatively large crystals of the material, gives a set of separate data from which the structure can be obtained.
However, most materials of technical interest cannot grow large crystals, so one has to resort to the powder diffraction technique using material in the form of very small crystallites. The drawback of this conventional powder method is that the diffraction peaks grossly overlap, thereby preventing proper determination of the structure. The "Rietveld Method" creates a virtual separation of these overlapping peaks, thereby allowing an accurate determination of the structure.
The method has been so successful that nowadays the structure of materials, in the form of powders, is routinely being determined, nearly as accurately as the results obtained by single crystal diffraction techniques. An even more widely used application of the method is in determining the components of chemical mixtures. This quantitative phase analysis is now routinely used in industries ranging from cement factories to the oil industry.
The success of the method can be gauged by the publication of more than a thousand scientific papers yearly using it:
Results of a search on Google Scholar
with the search string: ("rietveld refinement" OR "rietveld analysis" OR "rietveld method" OR "rietveld technique" OR "rietveld calculation" OR "rietveld quantitative phase analysis" OR "rietveld program") for the Rietveld Method,
the search string: (rietveld AND "quantitative phase analysis") for the Rietveld Quantitative Phase Analysis (RQPA) and
citations of the seminal paper "A Profile Refinement Method for Nuclear and Magnetic Structures", Rietveld,H.M.(1969), J.Appl. Cryst., 22, 65-71 from ISI Web of Knowledge.
Dr. Rietveld at
the neutron powder diffractometer at the High Flux Reactor of the
Foundation ECN in Petten, The Netherlands. (1987)
Dr. Robert L. Snyder presents Dr. Rietveld with the Barrett Award on behalf of the Denver X-ray
Conference Organizing Committee in Denver, USA, 6 August 2003.
Rossen, mayoress of Alkmaar, presents the decoration of the royal honour
of Officer in the Order of Oranje-Nassau to Dr. Rietveld for his outstanding contribution
to the field of chemistry in Alkmaar, The Netherlands, 29 October 2004.
Prof. Paolo Scardi, Chairman of the International Committee of the European Powder Diffraction Conference,
presents Dr. Rietveld with the 2010 EPDIC Award for Distinguished Powder Diffractionists,
in Darmstadt, Germany, 27 August 2010.