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 data grossly overlap, thereby preventing proper determination of the structure. The "Rietveld Method" creates an effective separation of these overlapping data, 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 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.
Dr. Rietveld at
the neutron powder diffractometer at the High Flux Reactor of the
Hugo Rietveld was
in The Hague, The Netherlands, on 7
March 1932. After completing Grammar School he went to Australia and
studied physics at the University of Western
In 1964 he obtained his Ph.D. degree with a thesis entitled "The Structure of p-Diphenylbenzene and Other Compounds", a single crystal neutron and X-ray diffraction study. This investigation was the first single crystal neutron diffraction study in Australia and was conducted at the nuclear reactor, HIFAR, in Sydney.
In 1964 he became a research officer at the Netherlands Energy Research Foundation ECN at Petten, The Netherlands, and was mainly involved in neutron powder diffraction studies of uranates and other ceramic compounds.
After a scientific and managerial career with ECN he retired in 1992.