The definitions for important Rietveld error indices are defined and discussed. It is shown that while smaller error index values indicate a better fit of a model to the data, wrong models with poor quality data may exhibit smaller values error index values than some superb models with very high quality data.

The ICDD's Powder Diffraction File™ (PDF®) is a database of inorganic and organic diffraction data used for phase identification and materials characterization by powder diffraction. The PDF has been available for over 75 years and finds application in X-ray, synchrotron, electron, and neutron diffraction analyses. With entries based on powder and single crystal data, the PDF is the only crystallographic database where every entry is editorially reviewed and marked with a quality mark that alerts the user to the reliability/quality of the submitted data. The editorial processes of ICDD's quality management system are unique in that they are ISO 9001:2015 certified. Initially offered as text on paper cards and books, the PDF evolved to a computer-readable database in the 1960s and today is both computer and web accessible. With data mining and phase identification software available in PDF products, and the databases’ compatibility with vendor (third party) software, the 1 000 000+ published PDF entries serve a wide range of disciplines covering academic, industrial, and government laboratories. Details describing the content of database entries are presented to enhance the use of the PDF.

The Reference Intensity Ratio (RIR) is a general, instrument-independent constant for use in quantitative phase analysis by the X-ray powder diffraction internal standard method. When the reference standard is corundum, RIR is known as I/Ic; These constants are collected in the Powder Diffraction File (1987), can be calculated, and can be measured. Recommended methods for accurate measurement of RIR constants are presented, and methods of using these constants for quantitative analysis are discussed. The numerous, complex constants in Copeland and Bragg's method introduced to account for superimposed lines can be simply expressed in terms of RIR constants and relative intensities. This formalism also permits introduction of constraints and supplemental equations based on elemental analysis.

X-ray diffraction in the Bragg-Brentano configuration (“XRD”) is a very established method. However, experimental evidence concerning its significant information depth, i.e. microstructure components from which maximum depth can affect the information evaluated from the acquired diffraction pattern, are scarce in the scientific literature. This depth is relevant to all XRD measurements performed on compact samples, especially layered composites and samples showing a crystallographic texture evolution. This article provides experimentally determined upper and lower limits to the significant information depth: XRD patterns acquired from a compact crystal layer through a layer of compact, amorphous glass indicate that the significant information depth of XRD using Cu Kα1 and Kα2 radiation is very likely larger than 48 μm, but smaller than 118 μm, in a material of the composition Mg2Al4Si5O18 with a density of ca. ~2.6 g/cm3. The depth of 48 μm correlates to the depth larger than the layer of material from which 90% of the reflected X-rays originate at 2Θ = 25.8°.

Methods extracting fast all the peak intensities from a complete powder diffraction pattern are reviewed. The genesis of the modern whole powder pattern decomposition methods (the so-called Pawley and Le Bail methods) is detailed and their importance and domains of application are decoded from the most cited papers citing them. It is concluded that these methods represented a decisive step toward the possibility to solve more easily, if not routinely, a structure solely from a powder sample. The review enlightens the contributions from the Louër’s group during the rising years 1987–1993.

HighScore with the Plus option (HighScore Plus) is the commercial powder diffraction analysis software from PANalytical. It has been in constant development over the last 13 years and has evolved into a very complete and mature product. In this paper, we present a brief overview of the suite focusing on the latest additions and its user-friendliness. The introduction briefly touches some basic ideas behind HighScore and the Plus option.

Commercial anodes with different state of charge are investigated by X-ray diffraction technique using Rietveld method for data collected with standard laboratory equipment. It is shown that full profile refinement gives good approximation for quantitative description of the charge/discharge process and may be used for estimation of real state of charge (SoC). Careful analysis of the diffraction profile with Rietveld method allows us to quantitatively distinguish the contribution of different LixC6 phases and estimate the real SoC.

Graphite oxide (GO) is generated by treating graphite with strong oxidizers. GO retains the structure of graphite, but does so with a larger and irregular basal plane spacing. The oxidation of graphite results in the formation of epoxide groups, as well as C–OH and COOH groups. It is the presence of some of these moieties that allows GO to be dispersed in water, allowing for its use in waterborne formulations. Although GO does not possess the electrical properties of single-sheet graphene, it can be swelled in water, which allows for intercalation of hydrophilic polymer between GO sheets, resulting in a composite that can be coated to produce a continuous film. After coating it may be possible to chemically convert GO to a reduced graphite oxide (r-GO) with improved electrical conductivity. X-ray diffraction (XRD) is ideally suited to evaluate GO–polymer composite samples for evidence of intercalation or exfoliation of GO. Examples of GO–polymer analysis by XRD are presented, along with results that demonstrate the effect of relative humidity (RH) on neat GO. Knowing the ambient RH during XRD data collection was found to be important to correctly assess the extent of polymer intercalation within the GO lattice.

Validating phase quantification procedures of powder X-ray diffraction (XRD) data for an implementation in an ISO/IEC 17025 accredited environment has been challenging due to a general lack of suitable certified reference materials. The preparation of highly pure and crystalline reference materials and mixtures thereof may exceed the costs for a profitable and justifiable implementation. This study presents a method for the validation of XRD phase quantifications based on semi-synthetic datasets that reduces the effort for a full method validation drastically. Datasets of nearly pure reference substances are stripped of impurity signals and rescaled to 100% crystallinity, thus eliminating the need for the preparation of ultra-pure and -crystalline materials. The processed datasets are then combined numerically while preserving all sample- and instrument-characteristic features of the peak profile, thereby creating multi-phase diffraction patterns of precisely known composition. The number of compositions and repetitions is only limited by computational power and storage capacity. These datasets can be used as input files for the phase quantification procedure, in which statistical validation parameters such as precision, accuracy, linearity, and limits of detection and quantification can be determined from a statistically sound number of datasets and compositions.