X‐ray powder diffraction structural characterization of Ba1‐xEuxTiO3 ternary oxides

The single‐phase Ba_1‐xEu_xTiO₃ (0.1≤x≤0.4) samples have been synthesized by solid state reaction under high pressure and ‐temperature. X‐ray powder diffraction data was determined by MS Modeling using Reflex Powder Indexing technique. The Ba_1‐xEu_xTiO₃ series exhibited an interesting orthorhombic‐tetragonal‐cubic structural transformation as Eu composition increases, the distinct change of the X‐ray diffraction peak profile in the vicinity of 45.5º is characteristic of structural transformation. (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)     

X‐ray Rotation‐Tilt‐Method — First Results of a new X‐ray Diffraction Technique

That from us as X‐ray Rotation‐Tilt Technique (XRT Method) designated procedure principle represents a world innovation and overcomes essential disadvantages of comparable diffraction techniques known up to now. Starting from the origin and the informational content of the XRT interferences a realization of a special equipment and selected examples of some first applications are presented.     

Crystal structure refinement of CuxAg1‐xInTe2 bulk material determined from X‐ray powder diffraction data using the Rietveld method

The influence of the Cu‐content in the quaternary compounds Cu_xAg_1‐xInTe₂ (0 ≤ x ≤1) on the structural properties of the bulk material was discussed. Bulk ingot materials of Cu_xAg_1‐xInTe₂ solid solutions (x = 0.0, 0.25, 0.50, 0.75 and 1.0) have been synthesized by fusion of the constituent elements in the stoichiometric ratios in vacuum‐sealed silica tubes. The materials compositions were confirmed by using energy dispersive analysis of X‐rays (EDAX). X‐ray powder diffraction measurements were performed for all the prepared samples at 300 K in step scanning mode. The analysis of X‐ray data has indicated that the crystal structure of the prepared materials with different compositions is single‐phase polycrystalline materials corresponding to the tetragonal chalcopyrite structure with space group I 2d. The crystal structural parameters were refined by Rietveld method using the Full Prof program. The refined lattice constants (a and c), anion positional parameter, u, and the determined bond distances and angles were found to vary with composition, x, attaining zero tetragonal distortion at x ≈ 0.75, which corresponds to an ideal tetragonal unit cell. (© 2004 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)     

Synthesis and X‐ray powder diffraction studies of semiconducting alloys in the system AgCd2‐xZnxGaS4

X‐ray powder technique was used in the investigation of AgCd₂GaS_4–'AgZn₂GaS₄' section to determine the region of AgCd₂GaS₄‐based solubility. It was established that the solid solution forms up to 75 mol.% 'AgZn₂GaS₄'. The refinement of AgCd_0.5Zn_1.5GaS₄ structure was performed. This alloy crystallizes in orthorhombic structure (space group Pmn2₁ ) with unit cell parameters a =0.78772(2), b =0.67221(2), c =0.64019(2) nm, V =0.33899(3) nm³. (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)     

Crystal structure refinement of the ternary compound Cu2SnTe3 by X‐ray powder diffraction

The ternary compound Cu₂SnTe₃ crystallizes in the Imm2 (Nº 44) space group, Z = 2, with a = 12.833(4) Å, b = 4.274(1) Å, c = 6.043(1) Å, V = 331.5(1) ų. Its structure was refined from X‐ray powder diffraction data using the Rietveld method. The refinement of 25 instrumental and structural variables led to R_p = 10.2%, R_wp = 11.8%, R_exp = 7.7%, R_B = 10.6%, S = 1.6 and χ² = 2.6, for 5501 step intensities and 163 independent reflections. This compound is isostructural with Cu₂GeSe₃, and consists of a three‐dimensional arrangement of slightly distorted CuTe₄ and SnTe₄ tetrahedra connected by common corners. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)     

Synthesis and X‐ray crystal structure investigations of the complexes of a proton sponge with selected inorganic acids: Crystal structure of DMAN.HI complex

A series of ionic complexes of 1,8–bis(dimethylamino)naphthalene with selected inorganic acids such as HCl, HBr, HI, HSCN and HBF₄ were synthesised and thoroughly investigated by means of powder diffractometry and analytical methods. The crystallographic data for these compounds as well as the results of the structure solution by powder diffraction methods of the 1,8–bis(dimethylamino)naphthalene.HI complex, which crystallizes in the monoclinic system, S.G. P2₁/c (14), a=7.999(2)Å, b=23.053(3)Å, c=7.948(1)Å, β=99.63°, R_F=17.1%, R_wp=15.5%, are discussed and presented in this work. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)     

X‐ray diffraction refinement of the crystal structure of anosovite prepared from leucoxene

The crystal structure of anosovite, (Ti_1.69Al_0.26Fe_0.05)³⁺(Ti_0.97Zr_0.03)⁴⁺O₅, prepared by carbothermal reduction of leucoxene under vacuum at 1450°C has been refined by Rietveld method using powder X‐ray diffraction data. It was found that it represents slightly monoclinically deformed pseudobrookite type structure with lattice parameters a = 9.8111 Å, b = 3.7509 Å, c = 9.9468 Å, β = 90.628°. (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)     

Grazing Incidence In‐plane Diffraction Measurement of In‐plane Mosaic with Microfocus X‐ray Tubes

The in‐plane mosaic structure of Au/Fe and GaN‐based epitaxial layers has been determined directly by laboratory‐based grazing incidence in‐plane x‐ray diffraction in which Bragg reflections normal to the plane of the wafer are probed. High intensity and acceptable signal‐to‐noise can be obtained with no modifications to commercially available equipment. Excellent agreement is obtained between measurements of the same Au/Fe multilayer samples at the European Synchrotron Radiation Facility in Grenoble and with the laboratory system employing a focused x‐ray beam from a microfocus generator. The technique is particularly important for the GaN‐based systems as it uniquely provides a measure of the so‐called twist mosaic independent of the out‐of plane (tilt) mosaic.     

X‐ray powder diffraction study of the semiconducting alloy Cu2Cd0.5Mn0.5GeSe4

The structure of the semiconducting alloy Cu₂Cd_0.5Mn_0.5GeSe₄ was refined from an X‐ray powder diffraction pattern using the Rietveld method. The present alloy crystallizes in the wurtz‐stannite structure, space group Pmn2₁ (N^o 31), and unit cell parameters values of a = 8.0253(2) Å, b = 6.8591(2) Å, c = 6.5734(2) Å and V = 361.84(2) ų. The structure exhibits a three‐dimensional arrangement of slightly distorted CuSe₄, Cd(Mn)Se₄ and GeSe₄ tetrahedras connected by corners. © 2004 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim     

Quantitative Determination of Crystalline Na5P3O10 –I (Form‐I) in Commercial Tripolyphosphate using X‐ray Diffraction Patterns

An x‐ray diffraction method (XRD) for quantitative determination of the crystalline Na₅P₃O₁₀‐I (Form‐I) in a mixture of Form‐I/Form‐II was applied for commercial pentasodium tripolyphosphate analysis. The XRD pattern of the Form‐I shows the unique non‐overlapping 2θ peak at a position of ≈ 21.8 deg. and also at ≈ 29.0 deg. (Cu radiation). The area (integral of the intensity) under the peaks is proportional to the amount of the Form‐I in the mixture covering the range up to 100 wt.%. That enables one to obtain a calibration line and to determine the amount of Form‐I in the mixture of Form‐I/Form‐II and also in commercial pentasodium tripolyphosphate. Commercial samples with high Form‐I concentration, in case they are contaminated with sodium pyrophosphate (Na₄P₂O₇), should be diluted with Form‐II to bring the concentration of the Form‐I below 50 wt.% in the analysed sample.     

Re‐Investigation of the Structure of 7Bi2O3 · 2WO3 by Single‐Crystal X‐ray Diffraction

The structure of the oxygen‐deficient compound 7Bi₂O₃ · 2WO₃, a fluorite‐derivative phase considered a candidate for electronic applications because of its high ionic conductivity, is investigated by singlecrystal X‐Ray diffraction employing Ag‐Kα radiation (λ = 0.5608 Å) to minimize the effect of the absorption by the heavy metals. The space‐group type is I4₁, the acentric subgroup of I4₁/a that was previously suggested from powder‐diffraction data and precession‐camera photographs. Lattice parameters are a = 12.513(2), c = 11.231(4) (Z = 2.5). The sample is twinned by syngonic merohedry, class I, with volume ratio of the individuals 0.58/0.42. The ordering of W partly confirms previous models, with one W fully occupying one of the sites on special position. However, the remaining W goes in a site on general position, which shares with Bi, resulting thus more diluted in the structure. The oxygen vacancies are partly ordered in three of the ten anion sites.     

Composition Dependency of Lattice Anisotropy of TlBX2‐type Chain Mixed Crystals

Variation of the lattice parameters of TlTl_1‐xIn_xSe₂ chain mixed crystals with composition have been studied by X‐ray diffraction technique. The lattice anisotropy ( c/a ) of the TlBX₂‐type mixed crystals changes linearly with substitution of the atoms located both at the center and at the vertices of the BX4 tetrahedra. A brief survey of the important features of the effect of isomorphic atom substitution on the lattice anisotropy of TlBX₂‐type mixed crystals with chain structure has been presented.     

Observation of the δ to ε Zr‐hydride transition by in‐situ synchrotron X‐ray diffraction

We investigate the formation and dissolution of hydrides in commercially pure zirconium powder in‐situ using high‐energy synchrotron X‐ray radiation. Experimental results showed a continuous phase transition between the δ and ε zirconium hydride phases with indication of a second order phase transformation.     

An Investigation on the Lattice Distortion in Urea and KCl Doped KDP Single Crystals by X‐ray Diffraction Studies

Potassium dihydrogen phosphate (KDP) doped with different mole concentrations of Urea and KCl were grown using low temperature solution growth technique. X‐ray diffraction studies were carried out on the grown crystals using a Shimadzu X‐ray diffractometer with CuKD radiation. X‐ray study revealed that the structures of the doped crystals are slightly distorted compared to the pure KDP crystal. This may be attributed to strains on the lattice by the adsorption of urea and KCl.     

X‐ray structural phase analysis of CdTe semiconductor annealed in air

X‐ray structural phase analysis of CdTe semiconductor, thermally annealed in air at temperature range 373‐773 K and annealing time 24 hrs, is investigated applying Rietveld method. The results showed that at low temperatures < 523 K, oxygen diffuses into the (1/21/21/2) interstitial sites of the CdTe lattice and its relative occupancy increases with the annealing temperature. For higher temperatures ≥ 523 K, the thermally grown oxide CdTeO₃ phase is developed on expense of CdTe phase. The percentage phase abundance of each phase is determined at each temperature applying a standardless method. The rate of oxidation with temperature is found to be non‐linear.     

Synthesis,spectroscopic studies and ab‐initio structure determination from X‐ray powder diffraction of bis‐(N‐3‐acetophenylsalicylaldiminato)copper(II)

The synthesis, spectroscopic studies and crystal structure determination from X‐ray powder diffraction have been carried out for bis‐(N‐3‐acetophenylsalicylaldiminato)copper(II). The structure is triclinic, space group P1 with unit cell dimensions a = 11.817(1) Å, b = 12.087(1) Å, c = 9.210(1) Å, α = 102.62(1)°, β = 111.16(1)°, γ = 86.15(1)°, V = 1197.0(2)ų, Z = 2. The structure has been solved by Monte Carlo simulated annealing approach and refined by GSAS package. The final Rp value was 8.68%. The coordination geometry around the copper atom in the complex is intermediate between square‐planar and tetrahedral with two salicylaldimine ligands in trans arrangement. Intermolecular C–H…O hydrogen bonds between molecules related by translation generate infinite chains along [010] direction. The molecular chains are linked via additional C–H…O hydrogen bonds to form a three‐dimensional supramolecular network. (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)     

The crystal structure of α‐SrGaBO4

A new compound α‐SrGaBO₄ has been synthesized by solid state reaction at high temperatures, and its structure has been solved by direct methods from powder X‐ray diffraction. α‐SrGaBO₄ has an orthorhombic system, Pccn space group, with lattice parameters a = 15.3154(7) Å, b = 8.9186(4) Å, c = 5.8130(3) Å, and Z = 8. The structure consists of infinite chains run parallel to the c axis and built up of GaO₄ tetrahedral and BO₃ triangles. The basic unit of these chains is a six ‐ membered Ga₂BO₈ ring formed by two GaO₄ tetrahedra and one BO₃ triangles. The Sr atom is bonded to eight oxygen atoms. The strontium atoms serve to hold the chains together through co‐ordination with oxygen atoms. DTA curve of noncrystalline glassy SrGaBO₄ was discussed. The XRD results show no phase transition occurs between ‐173 °C and 127 °C. (© 2004 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)     

X‐ray diffraction analysis of powder and thin film of (Gd1‐x Yx)2O3 prepared by sol‐gel process

The mixed oxide (Gd_1‐xY_x)₂O₃ (0.0 ≤ x ≤ 1.0) were synthesized, as powder and thin film, by a sol‐gel process. X‐ray diffraction data were collected and crystal structure and microstructure analysis were performed using Rietveld refinement method. All samples were found to have the same crystal system and formed solid solutions over the whole range of x. The cationic distribution, Gd³⁺ and Y³⁺, over the two non‐equivalent sites 8b and 24d of the space group Ia3 is found to be random for all values of (x). The lattice parameter is found to vary linearly with the composition (x). Replacing Gd³⁺ and Y³⁺ by each other introduces a systemic decrease in the x‐coordinate of cation position (24d) and slight changes in the oxygen coordinates. Crystallite size and microstrain analysis is performed along different crystallographic directions and anisotropic changes are found with the composition parameter (x). The average crystallite size ranges from 75 to 149 nm and the r.m.s strain from 0.027 to 0.068 x10^‐2. Textured Gd_1.841Y_0.159O₃ (400) buffer layers, with a high degree of alignment in both out‐plane and in‐plan, are successfully grown on cube textured Ni (001) tape substrates by sol–gel dip coating process. The resulting buffer layers are crack‐free, pinhole‐free, dense and smooth. YbBa₂Cu₃O_7‐x (YbBCO) thin film could be (00l) epitaxially grown on the obtained buffer layer using sol–gel dipping technique. (© 2007 WILEY ‐VCH Verlag GmbH & Co. KGaA, Weinheim)     

X‐ray powder diffraction structural characterization of iron(III) chloro‐ and bromo‐complexes of triphenylphosphine oxide

Iron (III) complexes of the composition [FeX₂(OPPh₃)₄][FeX₄], where X is Cl or Br were synthesised by several methods. It was found that each particular synthesis has yielded solids with slightly different powder patterns and also their comparison to those of calculated from single crystal data showed remarkable differences. A series of constrained Rietveld refinements has been performed on the title complexes to explain these differences. In a course of Rietveld refinement it was found that preferred orientation is not the only factor affecting the shape of the pattern and atoms parameters were included into refinement too. The results of Rietveld refinement allowed to conclude that the structures of compounds prepared by different methods are identical. In addition, it was shown that also in the case of rather complicated structure like the title complexes the powder diffraction method can lead to reasonable results.     

Crystal structures of X‐phase in the Sb–Te binary alloy system

It is well known that the Sb–Te binary system has a large number of incommensurately or commensurately modulated structures between Sb and Sb₂Te₃ compounds. These structures, which are long‐period trigonal stacking structures, possess their own modulation period γ, according to their composition in the thermal equilibrium. However, the structure of sputtered Sb–Te films with various compositions between the two compounds at both ends formed in a non‐thermal equilibrium showed smaller γ values, than those expected from their compositions without exception. A smaller γ value implies that its structure is closer to that of Sb with the shortest period in all Sb–Te modulated structures. With increase in temperature, all these transient structures with smaller γ, however, became stable, accompanying an increase of γ to acquire their original modulated structures.