Simultaneous Determination of the Lattice Constant and Elastics Strain in Cubic Single Crystal

1985 ◽  
Vol 29 ◽  
pp. 387-394 ◽  
Author(s):  
Balder Ortner

In epitaxial single crystal growing it happens very often that the composition of the grown film, say AxB1-x C, is not known exactly. Usually it would be possible to find out that compositions imply by determining the lattice constants of the film. The problem of such a measurement lies in the fact of internal and unknown stresses in the film. On the other side the knowledge of the state of stress σ and strain ε can also be of great importance. To calculate the stresses from X- ray measurements we need the lattice constants in the unstrained condition.Hornstra and Bartels have shown that the lattice constant can be det ermined by X-ray measurements if the strain is isotropic in the film plane. In the following we show that the lattice constant and the full strain tensor can be calculated fromat least four X- ray measurements also in the general case.

2005 ◽  
Vol 38 (4) ◽  
pp. 678-684 ◽  
Author(s):  
Balder Ortner

A method for the X-ray determination of lattice-plane distances is given. Similar to Bond's method, it is based on the measurement of rocking curves, with some advantages and disadvantages compared with the former method. The new method is especially designed for single-crystal stress measurement. Its usefulness is demonstrated in two examples of lattice-constant and stress measurement.


1967 ◽  
Vol 22 (1) ◽  
pp. 92-95 ◽  
Author(s):  
W. Witt

An absolute precision determination of lattice constants by electron diffraction is made with thin monocrystalline films of germanium and aluminium, having a thickness between 1000 and 5000 A. The films are prepared from the bulk material by mechanical polishing and subsequent chemical polishing or etching. The obtained values for the lattice constant α of both materials are within the accuracy Δα/α= ±3·10-5 of measurement in full agreement with the corresponding values obtained by X-ray diffraction (Smakula and Kalnajs).


1993 ◽  
Vol 46 (1) ◽  
pp. 127 ◽  
Author(s):  
LM Engelhardt ◽  
JM Harrowfield ◽  
AM Sargeson ◽  
AH White

The synthesis and single-crystal X-ray structure determination of the title compound are described. Crystals are monoclinic, P 21, a 16.164(9), b 8.277(3), c 8.829(4) Ǻ, β 102.86(4)°, Z 2; 2666 independent 'observed' diffractometer data [I > 3σ(I)] were refined to a residual of 0.045. The cation is unusual amongst complexes of sarcophagine (3,6,10,13,16,19-hexaazabicyclo[6.6.6]icosane) cage amines in adopting a lel2ob conformation, seemingly in response to hydrogen bonding/crystal packing forces. In consequence, unlike the tetranitrate analogue in which Ni-N bond distances are dispersed over a narrow range (2.097(5)-2.119(5) Ǻ; mean 2.109 Ǻ], the coordination sphere is more distorted with one pair of Ni-N distances, cis to each other, being short at 2.081(5) and 2.086(5) Ǻ, while the other four are long, ranging from 2.116(5) to 2.135(5) Ǻ, the mean of this array being 2.111 Ǻ.


1968 ◽  
Vol 7 (9) ◽  
pp. 977-981 ◽  
Author(s):  
Atsushi Okazaki ◽  
Noboru Tsukuda ◽  
Hiroshi Iwanaga ◽  
Masaru Kawaminami

2013 ◽  
Vol 69 (2) ◽  
pp. i8-i9 ◽  
Author(s):  
Benjamin N. Schumer ◽  
Robert T. Downs ◽  
Kenneth J. Domanik ◽  
Marcelo B Andrade ◽  
Marcus J. Origlieri

Pirquitasite, ideally Ag2ZnSnS4(disilver zinc tin tetrasulfide), exhibits tetragonal symmetry and is a member of the stannite group that has the general formulaA2BCX4, withA= Ag, Cu;B= Zn, Cd, Fe, Cu, Hg;C= Sn, Ge, Sb, As; andX= S, Se. In this study, single-crystal X-ray diffraction data are used to determine the structure of pirquitasite from a twinned crystal from the type locality, the Pirquitas deposit, Jujuy Province, Argentina, with anisotropic displacement parameters for all atoms, and a measured composition of (Ag1.87Cu0.13)(Zn0.61Fe0.36Cd0.03)SnS4. One Ag atom is located on Wyckoff site Wyckoff 2a(symmetry -4..), the other Ag atom is statistically disordered with minor amounts of Cu and is located on 2c(-4..), the (Zn, Fe, Cd) site on 2d(-4..), Sn on 2b(-4..), and S on general site 8g. This is the first determination of the crystal structure of pirquitasite, and our data indicate that the space group of pirquitasite isI-4, rather thanI-42mas previously suggested. The structure was refined under consideration of twinning by inversion [twin ratio of the components 0.91 (6):0.09 (6)].


1988 ◽  
Vol 41 (9) ◽  
pp. 1465 ◽  
Author(s):  
LM Engelhardt ◽  
BM Furphy ◽  
JM Harrowfield ◽  
DL Kepert ◽  
AH White ◽  
...  

The possible nature of p-t-butyl-calix [6] arene complexes of lanthanide elements has been explored by determination of the single-crystal X-ray structure of a complex with a 1:2 europium/ ligand ratio, obtained from dimethylformamide (dmf ≡ Me2NCHO) solution. This complex is formulated as [ Eu (LH4)(Me2NCHO)6(OH)].LH6.~4Me2NCHO (LH6 = p-t-butyl-calix [6] arene) on the basis of the structure determination. Crystals are monoclinic, P21/n, a 36.11(3), b 23.35(2), c 21.85(2)Ǻ, β 97.46(6)°, Z = 4 formula units; R was 0.11 for 8488 'observed' reflections. The complex is remarkable in that the only interaction of either of the two calixarene ligands (one presumably doubly or triply deprotonated ) with the eight-coordinate europium atom is by way of one behaving as monodentate, the other having no interaction. Eu -O( calix ) is 2.35(1) Ǻ; Eu -O( dmf )6 range from 2.38(2) to 2.49(2)Ǻ, and Eu -O(H ½?) is 2.49(2)Ǻ.


2020 ◽  
Author(s):  
Keishiro Yamashita ◽  
Kazuki Komatsu ◽  
Hiroyuki Kagi

An crystal-growth technique for single crystal x-ray structure analysis of high-pressure forms of hydrogen-bonded crystals is proposed. We used alcohol mixture (methanol: ethanol = 4:1 in volumetric ratio), which is a widely used pressure transmitting medium, inhibiting the nucleation and growth of unwanted crystals. In this paper, two kinds of single crystals which have not been obtained using a conventional experimental technique were obtained using this technique: ice VI at 1.99 GPa and MgCl<sub>2</sub>·7H<sub>2</sub>O at 2.50 GPa at room temperature. Here we first report the crystal structure of MgCl2·7H2O. This technique simultaneously meets the requirement of hydrostaticity for high-pressure experiments and has feasibility for further in-situ measurements.


1992 ◽  
Vol 47 (10) ◽  
pp. 1351-1354 ◽  
Author(s):  
Viktor Keimes ◽  
Albrecht Mewis

The compounds Mg2Ni3P and Mg2Ni3As were prepared by heating the elements. Their structures have been determined from single-crystal X-ray data. The structure of the phosphide is a rhombohedral ternary variant of the cubic Laves structure type MgCu2 (R 3̄ m; hexagonal lattice constants: a = 4.971(0) Å, c = 10.961(2) Å). The ordered substitution of one quarter of the metal atoms by phosphorus and the resulting shorter distances are responsible for the rhombohedral symmetry.The arsenide crystallizes in the MgCu2 type structure (Fd 3 m; a = 6.891(1)A, composition Mg2Ni3As) with a statistic distribution of the Ni and As atoms; the relevant homogeneity range extends from Mg2Ni2.9As1.1 to Mg2Ni3.5As0.5.


1975 ◽  
Vol 68 ◽  
pp. 239-241
Author(s):  
John C. Brown ◽  
H. F. Van Beek

SummaryThe importance and difficulties of determining the height of hard X-ray sources in the solar atmosphere, in order to distinguish source models, have been discussed by Brown and McClymont (1974) and also in this Symposium (Brown, 1975; Datlowe, 1975). Theoretical predictions of this height, h, range between and 105 km above the photosphere for different models (Brown and McClymont, 1974; McClymont and Brown, 1974). Equally diverse values have been inferred from observations of synchronous chromospheric EUV bursts (Kane and Donnelly, 1971) on the one hand and from apparently behind-the-limb events (e.g. Datlowe, 1975) on the other.


Author(s):  
Süheyla Özbey ◽  
Nilgün Karalı ◽  
Aysel Gürsoy

AbstractIn this study 4-(3-coumarinyl)-3-benzyl-4-thi azolin-2-one 4-methylbenzylidenehydrazone 3 was synthesised. An independent proof of the thiazolylhydrazone structure of 3 was achieved by single crystal X-ray diffraction analysis. Elemental analyses and spectral data (IR,


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