X-ray powder diffraction data, unit-cell parameters, and space group for a new bis(β-diiminato) Cu(II) complex, C44H54CuN4O4, are reported [a = 8.683(3) Å, b = 11.216(3) Å, c = 11.753(4) Å, α = 66.27(3), β = 84.61(3), γ = 78.85(3), unit-cell volume V = 1027.77 Å3, Z = 1, and space group P-1]. All measured lines were indexed and are consistent with the P-1 space group. No detectable impurity was observed.

Recently, a new experimental setup for quick X-ray reflectivity (q-XRR) measurements was proposed, which is based on simultaneous recording of an X-ray reflectivity curve over all angles of interest. This new setup for q-XRR allows measurements to be done within seconds, thus permitting studies of the time evolution of chemical, thermal, and mechanical changes at the surfaces and interfaces of different materials. Since the q-XRR measurement setup utilizes an extended X-ray source and detector, it is important to develop models and to account for the following two effects: (i) diffuse scattering associated with different points of the source and (ii) sample curvature. Models accounting for both effects are presented, and their influences on interpretation of the q-XRR measurement results are discussed.

Using high resolution powder neutron diffraction data, we show that there is a distinct anomaly in the structural noncentrosymmetry around the magnetic transition point TN for bulk and nanoscale BiFeO3. It appears that the structural noncentrosymmetry - which gives rise to the ferroelectric polarization - is suppressed anomalously by ~1% (of the average noncentrosymmetry at above the magnetic transition) in the bulk sample and by ~12% in the nanoscale sample as the magnetic transition is approached from higher temperature. This observation shows that the multiferroic coupling improves in the nanoscale sample which is expected to brighten the application prospects of nanoscale BiFeO3 in nanospintronics-based sensor devices.

PACS Nos. 75.70.Cn, 75.75.-c

X-ray powder diffraction data, unit-cell parameters, and space group for a new Ru Cl diamide complex, C36H48N2SO3RuCl, are reported [a = 12.487(4) Å, b = 16.624(5) Å, c = 17.230(3) Å, unit-cell volume V = 3576,79 Å3, Z = 4, and space group P212121]. All measured lines were indexed and are consistent with the P212121 space group. No detectable impurity was observed.

Eu3+-doped SmBa3B9O18 luminescent materials were synthesized by high temperature solid state reactions. The structure and photoluminescence properties of Sm(1−x)EuxBa3B9O18 (x = 0.2, 0.4, and 0.6) were investigated by X-ray diffraction, scanning electron microscopy, energy dispersive X-ray spectroscopy, and photoluminescence spectra. The results show that doping of Eu3+ ions does not change the structure of SmBa3B9O18. The luminescence is mainly the characteristic Eu3+ ion luminescence. No concentration quenching processes occur with the increment of Eu3+ concentration. The work implies that SmBa3B9O18 is a potential host material and europium-doped SmBa3B9O18 may find application in display and optical devices.

The effect of Dy3+ doping at A-site in hexagonal YMnO3 on the microstructure and magnetic properties was studied. Polycrystalline Y1−xDyxMnO3 samples with x ranging from 0 to 1 were synthesized by the solid-state reaction method. The microstructures of all the samples were studied by X-ray diffraction, which shows that Y1−xDyxMnO3 with a low concentration (x ≤ 0.5) of Dy3+ retains a hexagonal symmetry. The crystal structure refinements of the hexagonal Y1−xDyxMnO3 using the Rietveld method show that the unit-cell parameters of a, c, and unit-cell volume increase with increasing Dy doping, while the MnO5 trigonal bipyramids remain almost unchanged. The remarkable increasing of magnetic moment at a low temperature with increasing the Dy3+ doping concentration is ascribed to the spin order of Dy3+ and the increasing Dy3+–Mn3+ coupling and Mn3+–O–O–Mn3+ interaction.

Ab initio X-ray powder diffraction structural analyses from laboratory data have been widely employed in the characterization of coordination polymers not affording single crystals of suitable quality to undergo conventional structural determinations. This is particularly true for coordination polymers built upon strong ligand-to-metal bonds, as those formed by anionic, nitrogen-based heterocycles - pyrazolates, imidazolates, pyrimidinolates and more complex moieties derived therefrom. More than one hundred species belonging to this class have been structurally characterized in the last three decades, affording key, otherwise inaccessible stereochemical and supramolecolar features. This contribution summarizes our most recent experience in the XRPD structural characterization of pyrazolato-based coordination polymers, devoting a special consideration to the methodologies and tricks which allowed us to juxtapose the structural description of these materials to their physico-chemical and, above all, functional properties.

Crystal and X-ray powder diffraction data are presented for the Al3Ho2Si2 ternary compound. The powder pattern was indexed and refined on a monoclinic cell with the Al3Y2Si2 structure type with space group C12/m1, a = 10.1096(2) Å, b = 4.020(6) Å, c = 6.5734(6) Å, β = 100.848(2)°, V = 262.37 Å3, Z = 2ρx = 5.910 g cm−3, F30 = 142.8(0.006, 35), and RIR = 0.91.

In the last few decades, X-ray diffraction (XRD) systems have been paramount and irreplaceable in controlling bauxite exploration, as well as Bayer and reduction processes. XRD quantitative phase analysis in the aluminum industry witnessed a steady deployment of the Rietveld method, which at present progressively replaces existing methodologies in research and plant laboratories. Rietveld analysis not only helped to surpass traditional XRD calibration methods, it also opened the door for new applications previously not possible. The use of the Rietveld method to characterize selected materials unique to the aluminum industry, such as bauxite, red mud, and alumina is demonstrated and discussed. This paper also presents how synchrotron-based diffractograms obtained for bauxite and red mud samples allowed a much better understanding of mineralogical representation, and made it possible to leverage their Rietveld quantification. Despite clear advantages, the Rietveld method also has limitations that are revealed. For alumina phase quantification, a dedicated Rietveld analytical program was built with structure data for eight alumina mineralogical phases: alpha, beta (β-Al2O3 = Na2O•11Al2O3), delta, gamma (2), kappa, sigma, and theta. The paper gives unique examples of phase quantification in aluminas of various origins and phase composition.

X-ray powder diffraction data, unit-cell parameters, and space group for norandrostenedione, C18H24O2, are reported [a = 26.3955(15) Å, b = 8.0476(4) Å, c = 7.3002(3) Å, α = β = γ = 90°, unit-cell volume V = 1550.71 Å3, Z = 4, and space group P212121]. All measured lines were indexed and are consistent with the P212121 space group. No detectable impurity was observed.

Neutron diffraction studies of the La0.5Ba0.5CoO2.8 at the different temperatures has been performed. This solid solution crystallizes in the cubic structure (Pm3m space group) and exhibits below TN ~ 250K G-type antifferomagnetic ordering. Applied pressure suppresses magnetic ordering. Anomalous changes of the lattice parameters under pressure have been found.

A new methodology based on maximum likelihood estimation for structure refinement using powder diffraction data is proposed. The method can not only optimize the parameters adjusted in Rietveld refinement but also parameters to specify errors in a model for statistical properties of the observed intensity. The results of structure refinements with relation to fluorapatite Ca5(PO4)3F, anglesite PbSO4, and barite BaSO4 are demonstrated. The structure parameters of fluorapatite and barite optimized by the new method are closer to single-crystal data than those optimized by the Rietveld method, while the structure parameters of anglesite, whose values optimized by the Rietveld method are already in good agreement with the single-crystal data, are almost unchanged by the application of the new method.