Crystal Structure Analysis and Refinement Using Integrated Intensities from Accurate Profile Fits
Australian Journal of Physics
41(2) 283 - 296
Careful experimental techniques, especially using synchrotron radiation facilities, give well resolved diffraction patterns. Remaining overlapping peaks can be separated by profile fitting and profile analysis. The derived parameters are: peak position for lattice constants, integrated intensities for crystal structure work and halfwidth for line broadening analysis. Crystal structure refinements with the powder least squares program POWLS yield R factors routinely around R = 1·5% and as low as R = 0·6%. For actual structure analysis Fourier maps have been calculated in the case of the orthorhombic olivine analogue Mg2Ge04. Another non-trivial example concerns Ce02, where chemical bonding features are derived. From an analysis of anomalous dispersion in Yb20 3 the correction terms f' have been derived as a function of energy for four wavelengths measured close to the L-absorption edge of Yb.
Full text doi:10.1071/PH880283
© CSIRO 1988