Simon J. L. Billinge

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The program PDFFIT is designed for the full pro®le structural re®nement of the atomic pair distribution function (PDF). In contrast to conventional structure re®nement based on Bragg intensities, the PDF probes the local structure of the studied material. The program presented here allows the re®nement of atomic positions, anisotropic thermal parameters and(More)
Advances in materials science and molecular biology followed rapidly from the ability to characterize atomic structure using single crystals. Structure determination is more difficult if single crystals are not available. Many complex inorganic materials that are of interest in nanotechnology have no periodic long-range order and so their structures cannot(More)
V 2 O 3 nanocrystals can be synthesized through hydrothermal reduction in VO͑OH͒ 2 using hydrazine as a reducing agent. Addition of different ligands to the reaction produces nanoparticles, nanorods, and nanoplate-lets of different sizes. Small nanoparticles synthesized in this manner show suppression of the magnetic phase transition to lower temperatures.(More)
A study of the local atomic structure of the promising thermoelectric material ␤-Zn 4 Sb 3 , using atomic pair distribution function ͑PDF͒ analysis of x-ray-and neutron-diffraction data, suggests that the material is nano-structured. The local structure of the ␤ phase closely resembles that of the low-temperature ␣ phase. The ␣ structure contains ordered(More)
Optimal methods are explored for obtaining one-dimensional powder pattern intensities from two-dimensional planar detectors with good estimates of their standard deviations. Methods are described to estimate uncertainties when the same image is measured in multiple frames as well as from a single frame. The importance of considering the correlation of(More)
By means of normal-incidence, high-flux and high-energy X-rays, total scattering data for pair distribution function (PDF) analysis have been obtained from thin films (tf), suitable for local structure analysis. By using amorphous substrates as support for the films, the standard Rapid Acquisition PDF setup can be applied and the scattering signal from the(More)
We have studied the evolution with temperature of the local as well as the average crystal structure of MgB2 using the real-space atomic pair distribution function (PDF) measured by high resolution neutron powder diffraction. We have investigated the correlations of the B-B and B-Mg nearest neighbor pair motion by comparing, in the wide temperature range(More)
  • E S Božin, A Sartbaeva, H Zheng, S A Wells, J F Mitchell, Th Proffen +2 others
The local and average structure of the Ca endmember of the La1−xCaxMnO3 series has been investigated. Neutron powder diffraction based high real space resolution atomic pair distribution function (PDF) analysis, yielding the local atomic structure, and the corresponding Rietveld analysis yielding the average crystal structure show that the two structural(More)
Ultra-small, magic-sized metal nanoclusters represent an important new class of materials with properties between molecules and particles. However, their small size challenges the conventional methods for structure characterization. Here we present the structure of ultra-stable Au144(SR)60 magic-sized nanoclusters obtained from atomic pair distribution(More)