research papers
The technique of isotope-substitution neutron diffraction (ISND) and combined-data-set Rietveld analysis from powder neutron data of crystalline materials is presented and compared with single-data-set powder refinement methods. The rationale behind improvements in the precision and accuracy of the refined model as a result of reduction in parameter correlation in the least-squares technique is described. The improvements are demonstrated practically through a study of isotopically copper-substituted tenorite, CuO, at 2 and 300 K. Typically, the estimated errors on structural parameters from the combined analysis technique are 30% lower than separate single-data-set analyses. Comparison of the precision and accuracy of the structural models obtained from this investigation with previous single-crystal X-ray studies are also presented.
Keywords: isotope-substitution neutron diffraction; combined-data-set Rietveld analysis; neutron diffraction; powder diffraction; low-temperature diffraction.
Supporting information
Portable Document Format (PDF) file https://doi.org/10.1107/S0021889802022288/hw0100sup1.pdf |