Six different types of Majiang bronze drums from Hechi City, Guangxi, China were collected from the Guangxi Museum to characterize the original scheme of polychromy and materials used for the drums. The composition of all the samples were determined by using scanning electron microscopy with energy-dispersive X-ray spectroscopy. All the bronze drums contain mainly Cu, Sn, Pb, and As. Qualitative analysis of the structure by X-ray powder diffraction indicates that each of the six bronze drums contains four or five phases, namely (Cu, As), Pb, Cu3Sn, and Cu10Sn3 or Cu, Pb, As0.2Cu1.8, Cu3Sn, and Cu10Sn3. The Rietveld structural refinement is performed first time for the quantitative analysis of ancient bronze drums and inorganic cultural relics. This paper reports the result.

The crystal structure of a synthetic boehmite sample has been refined to an R of 0.047 in the space group Amam from X-ray powder diffraction data. Inclusion of hydrogen atoms and/or refinement in the space group A21am gave poorer results. Cell dimensions were determined as a = 3.6936 (± 0.0003), b = 12.214 (± 0.001), c = 2.8679 (± 0.0003) Å. All Al-O(OH) distances lie between 1.88 and 1.91 Å. Shared octahedral edges are 2.51–2.52 Å, and unshared octahedral edges are 2.86–2.87 Å, in excellent agreement with those for layered silicates. The O-H … O distance between contiguous octahedral sheets is 2.71 Å. The computed X-ray pattern matches closely with the experimental pattern, indicating the degree to which the crystal structure has been determined.

For more than 80 years, the scientific community has extensively used International Centre for Diffraction Data's (ICDD®) Powder Diffraction File (PDF®) for material characterization, including powder X-ray diffraction analysis. Historically, PDF was made available for two major material types: one for inorganic analysis and the other for organic analysis. In the early years of the PDF, this two-material approach was implemented due to limited computer capabilities. With Release 2024, ICDD provides a comprehensive database consisting of the entire PDF in one database called PDF-5+, comprised of more than one million entries (1,061,898). The PDF-5+ with a relational database (RDB) construct houses extensive chemical, physical, bibliographic, and crystallographic data, including atomic coordinates and raw data, enabling qualitative and quantitative phase analysis. This wealth of information in one database is advantageous for phase identification, materials characterization, and several data mining applications in materials science. A database of this size needs rigorous data curation and structural and chemical classifications to optimize pattern search/match and characterization methods. Each entry in the PDF has an editorially assigned quality mark. An editorial comment will describe the reason if an entry does not meet the top-quality mark. The editorial processes of ICDD's quality management system are unique in that they are ISO 9001:2015 certified. Among several classifications implemented in PDF-5+, subfiles (such as Bioactive, Pharmaceuticals, Minerals, etc.) directly impact the search/match in minimizing false positives. Scientists with specific field expertise continuously review these subfiles to maintain their quality. This paper describes the features of PDF with an emphasis on the newly released PDF-5+.

Materials in a high radioactive environment undergo structural changes. X-ray diffraction (XRD) is commonly used to study the micro-structural changes of such materials. Therefore, a safe procedure is required for the preparation of specimens. In this paper, a simple methodology for the preparation of radioactive powder specimens to be analyzed in a non-nuclearized laboratory diffractometer is presented. The process is carried out inside a shielded glove box, where the milling of the radioactive sample and specimen preparation occurs. Minimum amount of sample is required (<20 mg), which is drop-casted on a polyether ether ketone (PEEK) foil and glue-sealed inside a disposable plastic holder for a safe handling of the specimen. One example using neutron-irradiated granite is shown, where unit-cell parameters and crystal density of the main phases were calculated. The developed methodology represents an easy and affordable way to study neutron irradiated materials with low activity at laboratory scale.

X-ray diffraction (XRD) profile analysis of eight synthetic hematite samples was performed to identify the best parameters for determining the apparent mean crystallite dimension (D) and, consequently, surface area, The samples are comparable to soil hematite with respect to crystallinity. The procedure included: a) deconvolution of the XRD peaks to Gauss and Cauchy components and subtraction of the instrumental profile, b) determination of D from full-width at half-maximum, integral breadth, and integral breadth measurements of the Cauchy component, and c) comparison of deduced surface areas with those obtained by the N2-BET adsorption method. As expected, D values are strongly influenced by the broadening parameters. An appropriate selection of peaks is required to obtain size values along the crystallographic axes a (hkl: 110,300) and c (hkl: 104, 116) and to calculate reliable surface areas. Using the Cauchy component of the above peaks, the calculated surface areas compared well with those measured by the N2-BET adsorption method.

The deintercalation of a low-defect kaolinite intercalated with hydrazine was studied by X-ray diffraction, diffuse reflectance infrared spectroscopy (DRIFT), and Raman microscopy over 30 d. X-ray diffraction showed that the kaolinite was fully intercalated. More than 120 h were required for the hydrazine-intercalate to decompose. The Raman spectra of the hydrazine intercalate showed only a single band at 3620 cm−1, which was attributed to the innerhydroxyl group. Upon deintercalation, additional Raman bands were observed at 3626 and 3613 cm−1. These bands decreased in intensity with further deintercalation. As deintercalation proceeded, the bands assigned to the inner-surface hydroxyl groups at 3695, 3682, 3670, and 3650 cm−1 occurred and increased in intensity. DRIFT spectra showed two bands at 3620 and 3626 cm−1 for the fully intercalated kaolinite only. Upon deintercalation, an additional band assigned to intercalated water was observed at 3599 cm−1 and increased in intensity at the expense of the 3626-cm−1 band. Bands attributed to the innersurface hydroxyl groups increased in intensity with deintercalation. Both the Raman and DRIFT spectra showed complexity in the NH-stretching region with two sets of NH-symmetric and antisymmetric stretching bands. Deintercalation was followed by the loss of intensity of these bands. Significant changes were also observed in the hydroxyl deformation and water-bending modes as a result of deintercalation. A model of hydrazine intercalation of kaolinite based on the insertion of a hydrazine-water unit is proposed. The hydrated end of the hydrazine molecule hydrogen bonds with the innersurface hydroxyl groups resulting in the formation of a band at 3626 cm−1 in the DRIFT spectra.

Illite from the Potsdam Sandstone (lower Ordovician) of Northwestern New York was studied by powder X-ray diffraction, scanning electron microscopy, and chemically analyzed and dated by the K/Ar method. The texture and ages of 360 and 392 Ma on two samples establish that the mineral is authigenic and relatively uncontaminated by Precambrian detritus. Random powder X-ray diffraction patterns show sharp and relatively intense 02l and 11l reflections, indicating an ordered structure. Comparisons with calculated patterns demonstrated that the mineral is not the common 1M or 2M1 polytype. Instead, the experimental pattern is very similar to that of a 3T polytype, but it agrees better with the calculated pattern of the octahedral cis-vacant, noncentrosymmetric (space group C2) structure found by Méring and Oberlin (1967) and Tsipursky and Drits (1984) in smectites, proposed for mica by Drits et al. (1984) and found by Zvyagin et al. (1985).

X-ray diffraction patterns were obtained from rock fragments, < 1 μm randomly oriented freeze-dried powders, and < 1 μm oriented aggregates for 11 mixed-layered illite/smectite samples (K-bentonites) that cover the range from 14 to 100 percent expandable. In all cases, 00l and hkl comparisons show no evidence of laboratory induced artifacts. Either the laboratory procedures caused no disaggregation of fundamental illite particles, or, if they did, fundamental particle reaggregation during sample preparation duplicated the one and three-dimensional structures of the illite/smectite in the original, untreated rock.

Demodulation of the 20l, 13l reflections into a two-dimensional band shape occurred with increasing percent expandable layers in illite/smectite. This result strongly supports the contention that turbostratic displacements occur at the expandable interfaces between fundamental particles, and are limited to those sites.

A comparison of the quantities measured by powder X-ray diffraction and high resolution transmission electron microscope (TEM) lattice fringe image techniques for disordered crystals suggests that meaningful comparisons between the two methods can be made only if a sufficient number of images are recorded to define the statistical parameters of the disorder.

Intercalation of amino acids into 10.0-Å hydrated kaolinite was studied by powder X-ray diffraction (XRD), differential thermal analysis-thermal gravimetry (DTA-TG), and infrared (IR) spectroscopy. Intercalation was found to be dependent on the chain-length, pH, and the concentration of the amino acid zwitterion. Near the isoelectric point, fully intercalated phases were obtained in solutions of concentration >0.5–1 M for glycine (Gly), 2–3 M for β-alanine (β-Ala), and 12 M for both γ-aminobutyric acid (γ-Aba) and δ-aminovaleric acid (δ-Ava). ∊-aminocaproic acid (∊-Aca) with a long chain (C = 6) was only partially intercalated. Intercalated amino acid formed a mono-molecular arrangement with the alkyl chain tilting toward the layer at an angle related to H2O content. The compositions of the intercalates of the Gly and β-Ala are Al2Si2O5(OH)4·(Gly)0.67·0.24H2O and Al2Si2O5(OH)4·(β-Ala)0.63·0.25H2O, respectively, based on TG data. From IR data, Gly and β-Ala molecules are found intercalated as zwitterions and these molecules form hydrogen bonds with both the Al-OH and Si-O surfaces of kaolinite. Washing the intercalate with water produced a hydrated kaolinite, which may form a second amino-acid intercalate of high order. Thus, hydrated kaolinite intercalates or deintercalates amino acids depending on concentration and conditions.

A new ternary intermetallic compound Al3GaCu9 was synthesized experimentally. A high-quality powder diffraction pattern of the compound was collected by an X-ray diffractometer, and its crystal structure was determined using the Rietveld refinement method. Results show that the compound has a cubic cell with the Al4Cu9 structure type (space group $P\bar{4}3m$ and Pearson symbol cP52). The lattice parameter a = 8.7132(3) Å, unit-cell volume V = 661.52 Å3, calculated density Dcalc = 7.26 g/cm3, and Z = 4. The residual factors converge to Rp = 2.96%, Rwp = 4.06%, and Rexp = 2.57%. The experimentally obtained reference intensity ratio value is 7.04.

Auroselenide, ideally AuSe, is a new mineral from the Gaching ore occurrence of the Maletoyvayam deposit, Kamchatka peninsula, Russia. It occurs as anhedral grains up to 0.05 × 0.02 mm and as intergrowths up to 0.06 mm with maletoyvayamite–tolstykhite-series minerals, enclosed in native gold. Other associated minerals include pyrite, calaverite, fischesserite, gachingite, tetrahedrite-group minerals [stibiogoldfieldite, its As-analogue, tennantite-(Cu) and tetrahedrite-(Zn)], tripuhyite, minerals of the famatinite–luzonite and selenium–tellurium series, paraguanajuatite, petrovskaite, součekite and tiemannite. Auroselenide is bluish-grey, opaque with metallic lustre and grey streak. It is brittle and has an uneven fracture. Dcalc = 9.750 g/cm3. In reflected light, auroselenide is grey with a bluish shade. Bireflectance is very weak. No pleochroism and internal reflections are observed. In crossed polars, it is strongly anisotropic with bluish to brownish rotation tints. The reflectance values for wavelengths recommended by the Commission on Ore Mineralogy of the International Mineralogical Association are (Rmin/Rmax, %): 28.4/31.5 (470 nm), 30.2/33.3 (546 nm), 31.9/34.9 (589 nm) and 34.3/37.3 (650 nm). The principal bands in the Raman spectrum of auroselenide are at 93, 171, 200, 210 and 325 cm–1. The empirical formula calculated on the basis of 2 atoms per formula unit is (Au0.98Ag0.01)Σ0.99(Se0.79S0.17Te0.05)Σ1.01. Auroselenide is monoclinic, space group C2/m, a = 8.319(1), b = 3.616(1), c = 6.276(2) Å, β = 104.54(2)°, V = 182.74(5) Å3 and Z = 4. The strongest lines of the powder X-ray diffraction pattern [d, Å (I, %) (hkl)] are: 4.015 (54) (200); 3.033 (25) (${\bar 1}$11, 002); 2.780 (100) (${\bar 2}$02, 111); 2.172 (20) (${\bar 3}$11, 310); and 1.811 (25) (${\bar 1}$13). Auroselenide is the natural analogue of synthetic β-AuSe. The structural identity between them is confirmed by powder X-ray diffraction and Raman spectroscopy. The mineral is named according to its composition, as a combination of the main elements Au (aurum) and Se (selenium).

Tolstykhite, ideally Au3S4Te6, is a new mineral from the Gaching ore occurrence of the Maletoyvayam deposit, Kamchatka peninsula, Russia. It occurs as individual anhedral grains up to 0.05 mm or as intergrowths with native Se, native Te and tripuhyite. Other associated minerals include calaverite, fischesserite, Cu–Te-rich ‘fahlores' [stibiogoldfieldite, ‘arsenogoldfieldite', tennantite-(Cu), tetrahedrite-(Zn)], galena, gold, maletoyvayamite, minerals of famatinite–luzonite series, pyrite, baryte, ilmenite, magnetite, quartz and V-bearing rutile. Tolstykhite is bluish-grey, opaque with metallic lustre and grey streak. It is brittle and has an uneven fracture. Cleavage is good on {010} and {001}. Dcalc = 7.347 g/cm3. In reflected light, tolstykhite is grey with a bluish shade. No bireflectance, pleochroism and internal reflections are observed. In crossed polars, it is weakly anisotropic with bluish to brownish rotation tints. The reflectance values for wavelengths recommended by the Commission on Ore Mineralogy of the International Mineralogical Association are (Rmin/Rmax, %): 32.6/34.3 (470 nm), 32.4/34.1 (546 nm), 32.6/34.5 (589 nm) and 33.0/35.0 (650 nm). The Raman spectrum of tolstykhite contains the main bands at 297, 203, 181, 151 and 127 cm–1. The empirical formula calculated on the basis of 13 atoms per formula unit is (Au2.98Ag0.01)Σ2.99(S3.59Se0.41)Σ4.00Te6.01. Tolstykhite is triclinic, space group P$\bar{1}$, a = 8.977(5), b = 9.023(2), c = 9.342(6) Å, α = 94.03(3), β = 110.03(3), γ = 104.27(4)°, V = 679.0(3) Å3 and Z = 2. The strongest lines of the powder X-ray diffraction (XRD) pattern [d, Å (I, %) (hkl)] are: 8.59 (18) (010); 2.90 (100) (0$\bar{1}$3); 2.23 (13) (13$\bar{3}$); 1.89 (21) (13$\bar{4}$). Tolstykhite is the S-analogue of maletoyvayamite, Au3Se4Te6. The structural identity between them is confirmed by powder XRD and Raman spectroscopy. The mineral honours Russian mineralogist Dr. Nadezhda Dmitrievna Tolstykh for her contributions to the mineralogy of gold and platinum-group elements and the study of ore deposits.

The application of powder X-ray diffraction (PXRD) for the detection and quantification of low levels of a solid-state chemical impurity, BrettPhos oxide, in an active pharmaceutical ingredient is discussed. It is demonstrated that with appropriate methodology and experimentation, the impurity levels of as low as 0.07% w/w could be detected reliably and limit of quantification of 0.10% w/w could be achieved by PXRD, using a laboratory X-ray source. Method development, validation, and benchmarking using conventional high-performance liquid chromatography are presented in the manuscript highlighting the robustness and reproducibility of such measurements.

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.

A commercially available combined X-ray diffraction – differential scanning calorimetry (XRD-DSC) stage was adapted for studies of gas loading in microporous materials, including metal organic frameworks (MOFs). Insertion of a custom-built humid atmosphere swing chamber (HASC) between a humidity generator and the XRD-DSC stage facilitates both humid atmosphere and vacuum swing gas loading. The HASC is necessary to buffer between the humidity generator and the XRD-DSC stage, allowing the gas mixture to homogenize prior to sample exposure, so that both humid atmosphere and vacuum swings could be performed. The changes in XRD can be used to follow structural changes, including collapse, which is indicative of a lack of microporosity upon activation, and the flexibity of frameworks upon gas sorption–desorption cycles. Measurements of the area under the DSC curve allows for calculation of the isosteric heat of adsorption (Qst; kJ molGAS−1). Vacuum-atmosphere swing experiments performed at different pressure steps allow for the reconstruction of the enthalpy of gas adsorption before and after a phase transition. These modes of operation are illustrated in three case studies from a program of exploratory MOF synthesis used to discover novel materials for selective gas sorption from humid gas streams: (1) gas binding in Stony Brook metal organic framework-1, (2) zeolitic imidazolate framework-7 response to variable pressure vacuum-atmosphere swing, and (3) high throughput evaluation of the selectivity of novel MOFs synthesized from customized linkers.

Polycrystalline Ca0.925Ce0.075Mn0.9Fe0.1O3 were prepared by sol-gel reaction at 1073 K. The compound was analyzed by a powder X-ray diffraction technique and found to be in single phase. The unit-cell parameters and atomic positions were refined using General Structure Analysis to an orthorhombic structure with space group Pnma (#62) a = 5.281 90 (33) Å, b = 7.4968 (45) Å, and c = 5.302 90 (32) Å.

Respirable forms of crystalline silica including the mineral cristobalite are known carcinogens and the subject of increasing regulation and codes of good practice. Some bentonites may contain cristobalite, but more commonly they contain opal-CT, or opal-C, which can be confused with cristobalite. In the light of increasing regulation there is a clear need for simple and reliable methods that can distinguish cristobalite from the opals in bentonites and other clay materials. Here we propose the use of a simple NaOH method that is easily applied to bulk samples of bentonites. The method consists of boiling the clay in 0.5 M NaOH for 10 min and measuring the weight of undissolved solid. The method is shown to be accurate for both the identification and quantification of opal in bentonites since these phases are soluble when thus treated. It is also a straightforward method to distinguish the opals from cristobalite as the latter is essentially insoluble. Adoption by industry of a simple operationally-defined method such as this would be preferable to ad hoc reliance on direct instrumental methods alone such as X-ray powder diffraction, as the latter almost always require a large element of judgement and experience on the part of the analyst, although direct methods do need to be used in a supporting role.

Nestolaite (IMA 2013-074), CaSeO3·H2O, is a new mineral species from the Little Eva mine, Grand County, Utah, USA. It is named in honour of the prominent Italian mineralogist and crystallographer Fabrizio Nestola. The new mineral was found on sandstone matrix as rounded aggregates up to 2 mm across and up to 0.05 μm thick consisting of tightly intergrown oblique-angled, flattened to acicular crystals up to 30 μm long and up to 7 μm (very rarely up to 15 μm) thick. Nestolaite associates with cobaltomenite, gypsum, metarossite, orschallite and rossite. The new mineral is light violet and transparent with a white streak and vitreous lustre. The Mohs hardness is 2½. Nestolaite is brittle, has uneven fracture and perfect cleavage on {100}. The measured and calculated densities are Dmeas. = 3.18(2) g/cm3 and Dcalc. = 3.163 g/cm3. Optically, nestolaite is biaxial positive. The refractive indices are α = 1.642(3), β = 1.656(3), γ = 1.722(6). The measured 2V is 55(5)° and the calculated 2V is 51°. In transmitted light nestolaite is colourless. It does not show pleochroism but has strong pseudoabsorption caused by high birefringence. The chemical composition of nestolaite (wt.%, electronmicroprobe data) is: CaO 28.97, SeO2 61.14, H2O (calc.) 9.75, total 99.86. The empirical formula calculated on the basis of 4 O a.p.f.u. (atoms per formula unit) is Ca0.96Se1.02O3·H2O. The Raman spectrum is dominated by the Se–O stretching and O–Se–O bending vibrations of the pyramidal SeO3 groups and O–H stretching modes of the H2O molecules. The mineral is monoclinic, space group P21/c, with a = 7.6502(9), b = 6.7473(10), c = 7.9358(13) Å, β = 108.542 (12)°, V = 388.37(10) Å3 and Z = 4. The eight strongest powder X-ray diffraction lines are [dobs in Å(hkl) (Irel)]: 7.277 (100)(100), 4.949 (110)(37), 3.767 (002)(29), 3.630 (200)(58), 3.371 (020)(24), 3.163 (02)(74), 2.9783 (21)(74) and 2.7231 (112)(31). The crystal structure of nestolaite was determined by means of the Rietveld refinement from the powder data to Rwp = 0.019. Nestolaite possesses a layered structure consisting of CaΦ–SeO3 sheets, composed of edge-sharing polyhedra. Adjacent sheets are held by H bonds emanating from the single (H2O) group within the sheets. The nestolaite structure is topologically unique.

The unit-cell parameters of andalusite and sillimanite have been measured by high-T powder X-ray diffraction up to 1000°C at ambient pressure. Within the temperature range investigated, all the unit-cell parameters varied smoothly, indicating no phase transition. The volume-temperature data were fitted with a polynomial expression for the thermal expansion coefficient (αT = a0 + a1T + a2T-2). yielding a0 = 2.55(2) × 10–5K–1, al = 0 and a2 = 0 for andalusite, and a0 = 1.40(4) × 10–5K–1a1 = 7.1(8) × 10–9K–2 and a2 = 0 for sillimanite. Using the new thermal expansion data determined in the present study and compressional data from the literature, the P-T phase relations of the kyanite-andalusite-sillimanite system were calculated thermodynamically, with the invariant point located at ∼523°C and 3.93 kbar.