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X-ray powder diffraction data, unit-cell parameters and space group for the β-form of pigment yellow 181, C25H21N7O5, are reported [a = 22.556(6) Å, b = 4.9684(9) Å, c = 21.318(6) Å, β = 109.492(4)°, unit-cell volume V = 2252,1 Å3, Z = 4, space group P21/c]. All measured lines were indexed and are consistent with the P21/c space group. No detectable impurities were observed.
The X-ray diffraction patterns of two organic acids 1-naphthalenesulfonic acid dihydrate and 2-naphthalenesulfonic acid hydrate were measured at room temperature. Complexes of these acids with 1,8-bis(dimethylamino)naphthalene (DMAN) were synthesized, purified and investigated by means of X-ray powder diffraction. 1-Naphthalenesulfonic acid dihydrate as well as its complex with 1,8-bis(dimethylamino)naphthalene crystallize in the monoclinic system with unit cell parameters refined to a=0.91531(8) nm, b=0.7919(1) nm, c=0.8184(1) nm, β=101.618(9)° space group P21/m (11) and a=1.7781(4) nm, b=2.0122(4) nm, c=1.2337(2) nm, β=96.54(3)°, space group C2/m (12), respectively. 2-Naphthalenesulfonic acid hydrate crystallizes in the orthorhombic system with a=2.2749(3) nm, b=0.7745(1) nm, c=0.591 36(9) nm, space group Pnma, whereas its complex with 1,8-bis(dimethylamino)naphthalene crystallizes in the triclinic system a=1.3969(6) nm, b=1.4292(5) nm, c=1.1741(6) nm, α=90.93(3)°, β=98.14(3)°, γ=113.93(3)°, space group P-1 (2).
X-ray powder diffraction data, high resolution electron microscopy observation and refined unit cell parameters for δ-Al2O3 prepared from γ-Al2O3 are reported here. The new lattice parameters were a=7.9631(7) and c=23.3975(23) Å with space group P41212 (No. 92). The new data provide evidence for the simple tripling of the unit cell of the starting γ-Al2O3 spinel.
Results on using X-ray optics with a monocapillary attached to a microfocus Mo X-ray tube for a high-intensity XRF analysis are reported. Au-coated glass monocapillaries with 400 and 700 μm inner diameters were used to obtain focused and intensive incident Mo X-rays for the measurements of XRF intensities from pure metal samples. Intensity enhancements obtained by using the Au-coated monocapillaries were found to be up to 1.5 times higher than those obtained by using similar inner diameter uncoated glass capillaries. The XRF intensity profiles were measured by the wire scanning method to investigate the reasons. The traces of the incident X-rays were calculated by taking into account of X-ray total reflection of the incident X-rays from the inner wall of the capillaries. The calculated XRF intensity profiles agree with those of the measured XRF intensity profiles. The observed enhancements in XRF intensity were the results of the incident X-rays emitted from the Mo X-ray tube being totally reflected on the inner wall of the Au-coated monocapillaries.
Polycapillary optics are utilized in a wide variety of applications and are integral components in many state of the art instruments. Polycapillary optics operate by collecting X-rays and efficiently propagating them by total external reflection to form focused and parallel beams. We discuss the general parameters for designing these optics and provide specific examples on balancing the interrelations of beam flux, source size, focal spot-size, and beam divergence. The development of compact X-ray sources with characteristics tailored to match the requirements of polycapillary optics allows substantial reduction in size, weight, and power of complete X-ray systems. These compact systems have enabled the development of portable, remote, and in-line sensors for applications in industry, science and medicine. We present examples of the utility and potential of these optics for enhancing a wide variety of X-ray analyses.
A new variety of ammonium lanthanum sulfate, β-(NH4)La(SO4)2, was synthesized hydrothermally. The crystal structure was solved ab initio from powder diffraction data collected using a conventional X-ray source. The powder diffraction pattern was indexed by the successive dichotomy method: The symmetry is monoclinic, space group Pn, cell dimensions a=6.9365(4) Å, b=9.0055(5) Å, c=5.4541(4) Å, β=90.672(8)°, V=340.68(3) Å3 and Z=2 [M20=65, F30=124(0.0071,34)]. Direct methods were used for structure solution, and refinement of the atomic coordinates was carried out by the Rietveld method (RF=0.061, Rwp=0.099). The structure contains anionic layers built from lanthanum atoms ninefold coordinated to monodentate and bidentate sulfate oxygen atoms. Ammonium groups, which provide hydrogen bonds, are located between the layers. The crystal structure contrasts with that of the α phase, which is less dense by a factor of 4.4%.
Powder X-ray diffraction data for methionine sulfoxide, C5H11NO3S, obtained from the commercial amino acid, are presented in this work. Monoclinic cell parameters are: a=15.500 Å; b=3.820 Å; c=13.490 Å; β=97.300 °.
The anhydrous acid strontium oxalate Sr(HC2O4)⋅½(C2O4) was obtained by thermal decomposition of the hydrated acid strontium oxalate Sr(HC2O4)⋅½(C2O4)⋅H2O. This non-hygroscopic compound crystallizes in the space group P 21/c (No. 14) with unit cell parameters: a=0.796 61(7) nm, b=0.9205(1) nm, c=0.731 98(8) nm, and β=102.104(8)°. Final refinement of the X-ray powder data yielded RB=3.2% and Rwp=11.1% (background-corrected data). In this structure, Sr is eight-fold coordinated by O. These polyhedra are connected together by edge-sharing to form two-dimensional (2D) layers along the bc-plane, which means that there is an increased dimensionality from 1D to 2D with decreasing water content of the acid oxalates.
The subsolidus phase relations of the Dy-Fe-Al system have been investigated by means of X-ray powder diffraction. There are 5 ternary compounds, 10 binary compounds, and 21 three-phase regions in this system. The solid-solution regions of Dy(Fe1−xAlx)2, DyFe3−xAlx, Dy2(Fe1−xAlx)17, and DyFe12−xAlx have been determined based on the dependence of their unit-cell parameters on the Al content.
X-ray powder diffraction data for a new phase of dicalcium silicate, x-Ca2SiO4, are reported. The sample was prepared by the dehydration of hydrothermally synthesized α-type dicalcium silicate hydrate, Ca2(SiO4H)OH, at a temperature of 800 °C. Crystallographic data were Ca2SiO4, monoclinic, P21/c (No. 14), a=8.2127(5), b=9.7930(4), c=9.7954(5) Å, β=94.848(5)°, V=785.00(7) Å3, Z=8, and Dx=2.91 g·cm−3.
The structure of the new Y0.8Ca0.2Ba1.8La0.2Cu3Oy (YBLCO) compound was obtained at 298 K from X-ray powder diffraction data and refined by the Rietveld technique. YBLCO has a structure isotypical with YBa2Cu3Oy (YBCO) at room temperature. The crystal data are: Y0.81Ca0.19Ba1.8La0.2Cu3O7.08, Mw=657.69, orthorhombic system, space group Pmmm, a=3.8731(1) Å, b=3.8249(1) Å, c=11.6602(3) Å, V=172.740(13) Å3, Z=1, dx=6.325 g/cm3; the structure was refined with 37 parameters to Rwp=7.66%, Rp=5.86%, and Rexp=5.11% for 2001 data points. Moreover, the proportions of Ca and La were refined to be 0.19 and 0.2, in agreement with the stoichiometric proportion of 0.2.
The 1-[N-(methyl)-(3,5-dimethylphenylamino)]methylnaphthalene (chemical formula C20H21N) was prepared by means of a condensation between alpha-naphthylaldehyde and 3,5-dimethylaniline in anhydrous ethanol to obtain the aldimine (1) which was reduced with NaBH4 to afford the 1-[N-(3,5-dimethylphenylamino)]methylnaphtalene (2), and finally, the compound (3) was obtained by N-alkylation reaction of (2) with methyl iodine (CH3I) and potassium carbonate (K2CO3) in acetone. Final compound (3) was purified by chromatographic column. The XRPD pattern for the new compound, 1-[N-(methyl)-(3,5-dimethylphenylamino)]methylnaphthalene, was obtained. This compound crystallizes in monoclinic system with space group P21/a (No. 14) and refined unit-cell parameters a=13.260(4) Å, b=15.495(5) Å, c=7.719(5) Å, β=90.19(6), and V=1586(1) Å3.
A self-taught authority on electromagnetic theory, telegraphy and telephony, Oliver Heaviside (1850–1925) dedicated his adult life to the improvement of electrical technologies. Inspired by James Clerk Maxwell's field theory, he spent the 1880s presenting his ideas as a regular contributor to the weekly journal, The Electrician. The publication of Electrical Papers, a year after his election to the Royal Society in 1891, established his fame beyond the scientific community. An eccentric figure with an impish sense of humour, Heaviside's accessible style enabled him to educate an entire generation in the importance and application of electricity. In so doing he helped to establish that very British phenomenon, the garden-shed inventor. Combining articles on the electromagnetic wave surface and electromagnetic induction with notes on nomenclature and the self-induction of wires, Volume 2 serves as an excellent source for both electrical engineers and historians of science.
Using a recent proposed analysis procedure for quantitative phase determination by X-ray powder diffraction, YBa2Cu3O7−x solid state formation reaction kinetics at 900 °C was studied. Although there was the presence of partial amorphous components, it was possible to determine a reaction route for the synthesis of the title compound from X-ray powder diffraction data collected at various stages of the thermal treatment and using the Rietveld method for the quantitative determination of the phase composition
The characteristics of the (101) peak of α-quartz and the (104) peak of the NIST SRM 1976 alumina flat plate standard have been measured in dependence of time for 60 h with Cu-Kα1 radiation in Bragg-Brentano geometry with a Philips X’Pert diffractometer equipped with a primary Ge(111) monochromator. It was found that the reproducibility of the peak position and the peak shape falls well in the ±3σ range, whereas the peak intensity strongly depends on the power history of the X-ray generator and the temperature of the diffraction system. The effects on Rietveld refinements are discussed and recommendations are given for optimized data collection.
The crystal structures of four samples of anhydrite, CaSO4, were obtained by Rietveld refinements using synchrotron high-resolution powder X-ray diffraction (HRPXRD) data and space group Amma. As an example, for one sample of anhydrite from Hants County, Nova Scotia, the unit-cell parameters are a = 7.00032(2), b = 6.99234(1), c = 6.24097(1) Å, and V = 305.487(1) Å3 with a > b. The eight-coordinated Ca atom has an average <Ca-O> distance of 2.4667(4) Å. The tetrahedral SO4 group has two independent S-O distances of 1.484(1) to O1 and 1.478(1) Å to O2 and an average <S-O> distance of 1.4810(5) Å. The three independent O-S-O angles [108.99(8) × 1, 110.38(3) × 4, 106.34(9)° × 1; average <O-S-O> [6] = 109.47(2)°] and S-O distances indicate that the geometry of the SO4 group is quite distorted in anhydrite. The four anhydrite samples have structural trends where the a, b, and c unit-cell parameters increase linearly with increasing unit-cell volume, V, and their average <Ca-O> and <S-O> distances are nearly constant. The grand mean <Ca-O> = 2.4660(2) Å, and grand mean <S-O> = 1.4848(3) Å, the latter is longer than 1.480(1) Å in celestite, SrSO4, as expected.
Ternary Al-Cu-W alloys were investigated. The previously reported Al3Ti-type phase (space group I4/mmm) with the average composition Al67Cu11.5W21.5 was found to have a=3.7296(4) Å and c=8.3797(10) Å. The ternary phase forming around Al67Cu21W12 has a hexagonal structure with a=8.6594(13) Å and c=15.2677(21) Å.