The impact of background function on high accuracy Quantitative Rietveld Analysis (QRA): Application to NIST SRMs 676 and 656

摘要: The accuracy of Quantitative Rietveld Analysis (QRA) was examined in terms the plausibility set refined parameters as well realization expected quantitative result. This route pursued due to two mutually exclusive characteristics that a powder exhibiting calculated (ideal) diffraction intensity would possess; it have infinitesimal domains alleviate effects extinction but at same time surface area eliminate volume disordered or amorphous phase. specimens were mixtures NIST Standard Reference Material (SRM) 640b, silicon with mean particle size 7 {micro}m (certified respect lattice parameters), and SRM 676, an alumina submicrometer crystallite for analysis). Good agreement between determined by laser scattering measurements, its domain size, determining using Sabine model extinction, obtained use improved background functions refinements neutron time-of-flight (TOF) data. These data, conjunction other such temperature factors, led credible measurement content 676 verification thatmore » TOF data can yield unbiased results. A new analysis nitride certified {alpha}, {beta} (impurity) phase reference Results from XRD found be less sensitive function, through improvements achieved.« less