This paper presents a method of reducing the X-ray diffraction data collection time, while maintaining high data quality, suitable for Rietveld refinement. The approach taken here is that phases in general show peak broadening as well as a loss of intensity with increasing 2-theta. Thus, by splitting the full analyzed 2-theta range into regions and adjusting the step-size and counting time to a...

Simulations of 29Si and 23Na MAS NMR spectra indicate the presence of differing proportions of two polytypes and a third phase in three samples of penkvilksite, Na4Ti2Si8O22•5H2O. The most abundant peaks are assigned to the 2O and 1M polytypes, and a third set of peaks are provisionally assigned to a proposed 2M polytype. The quadrupolar interaction parameters for 23Na, Cq and , were calculated...

This is the fourth in a series of papers on Rietveld materials characterisation metrology presented at recent Denver X-ray Conferences [refs 1-3]. Reference 3 examined the management of the zero-point and specimen displacement corrections in extracting lattice parameters from BraggBrentano x-ray diffraction data by Rietveld analysis. This paper emphasises the importance of pre-determining the z...

-A structure refinement of kaolinite made using the Rietveld neutron profile refinement technique has given non-hydrogen atom positions which were not significantly different from those given by B. B. Zvyagin in i960. All of the hydrogen atoms have been located; the three inner-surface hydrogen atoms are involved in interlayer hydrogen bonds with lengths of 2.95(4), 2.95(4), and 3.06(4) ]k with...