Rietveld refinement of neutron, synchrotron and combined powder diffraction data of cement clinker

Abstract

Ordinary Portland-cement clinkers were characterised using neutron and synchrotron powder diffraction. Rietveld analysis was performed using individual as well as combined data. Comparisons were made between phase quantifications made using these different data sets, and with published results from other methods. Neutron results showed difficulty in distinguishing between tri- and dicalcium silicate phases, whilst synchrotron results compared well to other methods. Refinements were performed with and without refinement of the atomic positions of some atoms in the two main phases of a sample, and the results compared. Less than 1% adjustment in the atomic positions was found to decrease Bragg R-factors by about 20%.