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1.
Synthesis and X‐ray powder diffraction studies of semiconducting alloys in the system AgCd2‐xZnxGaS4
O. V. Parasyuk I. D. Olekseyuk O. A. Dzham V. I. Pekhnyo 《Crystal Research and Technology》2006,41(1):32-36
X‐ray powder technique was used in the investigation of AgCd2GaS4–'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 AgCd0.5Zn1.5GaS4 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) 相似文献
2.
The semimagnetic semiconductor alloy Zn0.5Mn0.5In2Te4 was refined from an X‐ray powder diffraction pattern using the Rietveld method. This compound crystallizes in the space group I42m (Nº 121), Z = 2, with unit cell parameters a = 6.1738(1) Å, c = 12.3572(4) Å, V = 471.00(2) Å3, c / a = 2.00. This material crystallizes in a stannite‐type structure. (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim) 相似文献
3.
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) Å3. Its structure was refined from X‐ray powder diffraction data using the Rietveld method. The refinement of 25 instrumental and structural variables led to Rp = 10.2%, Rwp = 11.8%, Rexp = 7.7%, RB = 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) 相似文献
4.
The influence of the Cu‐content in the quaternary compounds CuxAg1‐xInTe2 (0 ≤ x ≤1) on the structural properties of the bulk material was discussed. Bulk ingot materials of CuxAg1‐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) 相似文献
5.
Single crystals of the magnetic semiconductor CoIn0.5Cr1.5S4, belong to the system CoIn(2‐2X)Cr(2X)S4 with x = 0.75, was grown by the chemical transport method. X‐ray powder diffraction characterization by the Rietveld method indicated that CoIn0.5Cr1.5S4 crystallizes in the space group Fd‐3m, Z = 8, with a = 10.0700(6) Å and V = 1021.2(1) Å3, in a normal spinel structure. The temperature dependence of the DC magnetization suggests that the studied compound presents a ferromagnetic behavior with a Curie temperature Tc = 220 K. Sharp spin‐glass like behavior was found also. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim) 相似文献
6.
S. Banerjee A. K. Mukherjee I. Banerjee R. L. De M. A. Neumann D. Louer 《Crystal Research and Technology》2005,40(8):815-821
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)Å3, 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) 相似文献
7.
G. E. Delgado A. J. Mora J. E. Contreras P. Grima‐Gallardo S. Durn M. Muoz M. Quintero 《Crystal Research and Technology》2009,44(5):548-552
The crystal structure of the chalcogenide compounds CuFeAlSe3 and CuFeGaSe3, belonging to the system I‐II‐III‐III3, were characterized using X‐ray powder diffraction data. Both compounds crystallize in the tetragonal space group P42c (N° 112), Z = 1, with unit cell parameters a = 5.609(1) Å, c = 10.963(2) Å for CuFeAlSe3 and a = 5.6165(3) Å, c = 11.075(1) Å for CuFeGaSe3. These compounds are isostructural with CuFeInSe3, and have a normal adamantane structure. (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim) 相似文献
8.
V. Jorík I. Ondrejkovicov R. B. von Dreele H. Ehrenberg 《Crystal Research and Technology》2003,38(2):174-181
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. 相似文献
9.
The single‐phase Ba1‐xEuxTiO3 (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 Ba1‐xEuxTiO3 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) 相似文献
10.
The crystal structure of anosovite, (Ti1.69Al0.26Fe0.05)3+(Ti0.97Zr0.03)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) 相似文献
11.
Synthesis of InGaZnO4 at 20Kb and 50Kb produced a single crystal and a twinned crystal respectively. The X�ray diffraction crystal structure refinement (R1 = 0.015 and 0.019 respectively) and the Charge Distribution analysis are reported. Space group is R3m; cell parameters in hexagonal axes are a = 3.2990(2)Å, c = 26.1013(25)Å (20kb single crystal) and a = 3.3051(2)Å, c = 26.1029(19)Å (50kb twinned crystal). The cell volume is 246.01(3)Å3 and 246.94(3)Å3 respectively. The In is in regular octahedral coordination, whereas Ga/Zn are in trigonal bipyramid co‐ordination. Charge Distribution on cations (2.94 and 2.95 respectively vs. 3.0 for In, and 2.53 vs. 2.5 for Ga/Zn) shows that the structure is well refined. Charge Distribution on oxygens (—1.96 and —2.04 for O1 and O2, vs. —2.0) excludes the presence of valence unbalance effects. A possible structural role of the trigonal bipyramidal coordination is discussed. 相似文献
12.
V. Sagredo L. Betancourt L. M. de Chalbaud G. E. Delgado 《Crystal Research and Technology》2004,39(10):873-876
Single‐crystal of the CdGaCrSe(4‐X)S(X) system (x = 0; 1; 2; 3; 4) were grown by the chemical vapour‐phase transport technique. The crystals were obtaine by using CdCl2 as transporting agent for the composition with x = 1, and CrCl3 for those with x = 0; 2; 3 and 4. X‐ray powder diffraction analysis indicated that some of the samples crystallizes in the tetragonal system with space group I‐4 (CdGaCrSe3S , x = 1; CdGaCrSe2S2 , x = 2), or in a cubic system with space group Fd‐3m (CdGaCrSeS3, x = 3; CdGaCrS4, x = 4), however the sample of CdGaCrSe4 (x = 0) crystallizes in rhombohedral system. Magnetic measurements show significant changes in the magnetic interactions behaviour probably due to the anionic substitutions. (© 2004 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim) 相似文献
13.
A. Wierzbicka J. Z. Domagala M. Sarzynski Z. R. Zytkiewicz 《Crystal Research and Technology》2009,44(10):1089-1094
Spatially resolved X‐ray diffraction (SRXRD) is applied for micro‐imaging of strain in laterally modulated epitaxial structures. In GaAs layers grown by liquid phase epitaxial lateral overgrowth (ELO) on SiO2‐masked GaAs substrates a downward tilt of ELO wings caused by their interaction with the mask is observed. The distribution of the tilt magnitude across the wings width is determined with μm‐scale spatial resolution. This allows measuring of the shape of the lattice planes in individual ELO stripes. If a large area of the sample is studied the X‐ray imaging provides precise information on the tilt of an individual wing and its distribution. In heteroepitaxial GaSb/GaAs ELO layers local mosaicity in the wing area is found. By the SRXRD the size of microblocks and their relative misorientation were analyzed. Finally, the SRXRD technique was applied to study distribution of localized strain in AlGaN epilayers grown by MOVPE on bulk GaN substrates with AlN mask. X‐ray mapping proves that by mask patterning strain in AlGaN layer can be easily engineered, which opens a way to produce thicker, crack‐free AlGaN layers with a higher Al content needed in GaN‐based laser diodes. All these examples show that high spatial and angular resolutions offered by SRXRD makes the technique a powerful tool to study local lattice distortions in semiconductor microstructures. (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim) 相似文献
14.
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. 相似文献
15.
F. Emmerling G. Reck W. Kraus I. Orgzall B. Schulz 《Crystal Research and Technology》2008,43(1):99-107
The crystal structures of the 1,3,4 oxadiazole compounds N,N‐dimethyl‐N‐[4‐(1,3,4‐oxadiazol‐2‐yl)phenyl]amine ( 1 ) and 2‐methyl‐5‐phenyl‐1,3,4‐oxadiazole ( 2 ) have been determined. In case of 1 no adequate crystals were available; therefore the structure was solved at room temperature from X‐ray powder diffraction data using the method of simulated annealing. This solution is compared to a second one obtained by applying the molecular replacement method. Subsequent Rietveld refinements combined with the so called two stage method based on the data collected to 1.6 Å resolution yielded an Rwp value of 7.27% for 1 . Compound 1 crystallizes in the orthorhombic space group P212121 with lattice parameters of a = 7.599(4) Å, b = 6.004(2) Å, c = 21.736(3) Å. The crystal structure of 2 was solved by means of single crystal structure analysis (monoclinic space group P21/c, a = 8.010(3) Å, b = 10.783(4) Å, c = 19.234(7) Å, β = 90.794(9)°). (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim) 相似文献
16.
W. Wierzchowski K. Wieteska T. Balcer A. Malinowska W. Graeff W. Hofman 《Crystal Research and Technology》2007,42(12):1359-1363
SiC crystals of high structural perfection were investigated with several methods of X‐ray diffraction topography in Bragg‐case geometry. The methods included section and projection synchrotron white beam topography and monochromatic beam topography. The investigated 6H and 4H samples contained in large regions dislocations of density not exceeding 103 cm‐2. Most of them cannot be interpreted as hollow core dislocations (micro‐ or nano‐pipes). The concentration of the latter was lower than 102 cm‐2. The present investigation confirmed the possibility of revealing dislocations with all used methods. The quality of presently obtained Bragg‐case multi‐crystal and section images of dislocation enabled analysis based on comparison with numerically simulated images. The analysis confirmed the domination of screw‐type dislocations in the investigated crystals. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim) 相似文献
17.
T. Maimaitiyili A. Steuwer J. Blomqvist C. Bjerkn M.S. Blackmur O. Zanellato J. Andrieux F. Ribeiro 《Crystal Research and Technology》2016,51(11):663-670
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. 相似文献
18.
A. M. Moustafa R. E. Dinnebier S. T. Nasser M. Jansen 《Crystal Research and Technology》2008,43(2):205-213
The crystal structures of the dispiro compounds 1,3,4,8,10,11‐Hexaphenyl‐13‐methyl‐1,2,8,9,13‐pentaazadispiro[4.1.4.3]tetradeca‐2,9‐dien‐6‐one ( 3a ) and 4,11‐Bis(4‐methoxyphenyl)‐13‐methyl‐1,3,8,10‐tetraphenyl‐1,2,8,9,13‐pentaazadispiro‐[4.1.4.3]tetradeca‐2,9‐dien‐6‐one ( 3b ) have been determined at room temperature from X‐ray powder diffraction data using the method of simulated annealing as implemented in the programs DASH and TOPAS. Subsequent Rietveld refinements using the data collected to 1.5 Å resolution yielded R‐Bragg values of 2.2% for ( 3a ) and 3.7% for ( 3b ). It was found, that both compounds crystallize in the monoclinc space group P 21/n with lattice parameters of a = 17.1656(5) Å, b =13.8128(3) Å, c = 16.1016(5) Å, and β = 103.7330(2)° for ( 3a ) and a = 17.2529(8) Å, b = 13.8729(5) Å, c =16.1287(10) Å, and β = 103.6910(3)° for ( 3b ). Both compounds exhibit a distorted hexagonal close type of packing (hcp) of the molecular centers of gravity. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim) 相似文献
19.
M. Georgievskaya B. Albert R. Bubnova G. Cordier C. Bhtz S. Filatov 《Crystal Research and Technology》2008,43(11):1150-1160
In the potassium‐rich part of the binary system Na4B8O14‐K4B8O14 solid solutions have been found that can be described with the formula (Na1‐xKx)4B8O14 with 0.45 ≤ x < 1.0. The crystal structures of (Na0.25K0.75)4B8O14 and (Na0.45K0.55)4B8O14 were refined at room temperature by the Rietveld method. The solid solutions crystallize like K4B8O14 in the triclinic crystal system, space group P ‐1, with K partially substituted for Na. An ordered distribution of the alkali atoms over the four cation sites at room temperature has been discovered. The structure of (Na0.25K0.75)4B8O14 was also refined for data collected at 300 and 500 °C. The refinements show that sodium and potassium atoms are less ordered at higher temperatures. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim) 相似文献
20.
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. 相似文献