Determination of single-crystal elasticity constants in a cubic phase within a multiphase alloy: X-ray diffraction measurements and inverse-scale transition modelling

2005 ◽  
Vol 38 (1) ◽  
pp. 30-37 ◽  
Author(s):  
S. Fréour ◽  
D. Gloaguen ◽  
M. François ◽  
A. Perronnet ◽  
R. Guillén

The scope of this work is the determination of single-crystal elastic properties from X-ray diffraction stress analysis performed on multiphase polycrystals. An explicit three-scale multiphase inverse self-consistent model is developed in order to express the single-crystal elasticity constants of a cubic phase as a function of its X-ray elasticity constants. The model is verified in the case of single-phase materials. Finally, it is applied to a two-phase (α+β) titanium-based alloy (Ti-17) and, as a result, the Ti-17 β-phase single-crystal elasticity tensor is estimated.

2011 ◽  
Vol 681 ◽  
pp. 97-102 ◽  
Author(s):  
Sylvain Fréour ◽  
Emmanuel Lacoste ◽  
Manuel François ◽  
Ronald Guillén

The scope of this work is the determination of single-crystals elastic constants (SEC) from X-ray diffraction lattice strains measurements performed on multi-phase polycrystals submitted to mechanical load through a bending device. An explicit three scales inverse self-consistent model is developed in order to express the SEC of a cubic phase, embedded in a multi-phase polycrystal, as a function of its X-ray Elasticity Constants. Finally, it is applied to a two-phases (α+β) titanium based alloy (Ti-17), in order to estimate Ti-17 β-phase unknown SEC. The purpose of the present work is to account the proper microstructure of the material. In particular, the morphologic texture of Ti-17 a-phase, i.e. the relative disorientation of the needle-shaped grains constituting this phase, is considered owing to the so-called Generalized Self-Consistent model.


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,


2014 ◽  
Vol 70 (a1) ◽  
pp. C1560-C1560
Author(s):  
Fumiko Kimura ◽  
Wataru Oshima ◽  
Hiroko Matsumoto ◽  
Hidehiro Uekusa ◽  
Kazuaki Aburaya ◽  
...  

In pharmaceutical sciences, the crystal structure is of primary importance because it influences drug efficacy. Due to difficulties of growing a large single crystal suitable for the single crystal X-ray diffraction analysis, powder diffraction method is widely used. In powder method, two-dimensional diffraction information is projected onto one dimension, which impairs the accuracy of the resulting crystal structure. To overcome this problem, we recently proposed a novel method of fabricating a magnetically oriented microcrystal array (MOMA), a composite in which microcrystals are aligned three-dimensionally in a polymer matrix. The X-ray diffraction of the MOMA is equivalent to that of the corresponding large single crystal, enabling the determination of the crystal lattice parameters and crystal structure of the embedded microcrytals.[1-3] Because we make use of the diamagnetic anisotropy of crystal, those crystals that exhibit small magnetic anisotropy do not take sufficient three-dimensional alignment. However, even for these crystals that only align uniaxially, the determination of the crystal lattice parameters can be easily made compared with the determination by powder diffraction pattern. Once these parameters are determined, crystal structure can be determined by X-ray powder diffraction method. In this paper, we demonstrate possibility of the MOMA method to assist the structure analysis through X-ray powder and single crystal diffraction methods. We applied the MOMA method to various microcrystalline powders including L-alanine, 1,3,5-triphenyl benzene, and cellobiose. The obtained MOMAs exhibited well-resolved diffraction spots, and we succeeded in determination of the crystal lattice parameters and crystal structure analysis.


IUCrData ◽  
2019 ◽  
Vol 4 (11) ◽  
Author(s):  
Artem V. Malin ◽  
Sergei I. Ivlev ◽  
Roman V. Ostvald ◽  
Florian Kraus

Single crystals of rubidium tetrafluoridobromate(III), RbBrF4, were grown by melting and recrystallizing RbBrF4 from its melt. This is the first determination of the crystal structure of RbBrF4 using single-crystal X-ray diffraction data. We confirmed that the structure contains square-planar [BrF4]− anions and rubidium cations that are coordinated by F atoms in a square-antiprismatic manner. The compound crystallizes in the KBrF4 structure type. Atomic coordinates and bond lengths and angles were determined with higher precision than in a previous report based on powder X-ray diffraction data [Ivlev et al. (2015). Z. Anorg. Allg. Chem. 641, 2593–2598].


2020 ◽  
Vol 53 (1) ◽  
pp. 99-106
Author(s):  
Andreas Johannes ◽  
Jura Rensberg ◽  
Tilman A. Grünewald ◽  
Philipp Schöppe ◽  
Maurizio Ritzer ◽  
...  

This work showcases a method to map the full deformation tensor in a single micro-sized crystal. It is shown that measuring the position of two Bragg reflections in reciprocal space is sufficient to obtain the full deformation tensor, if the condition of incompressibility of the material is imposed. This method is used to reveal the surface tension induced deformation at the edges of an as-grown single-crystal VO2 microwire. All components of the deformation tensor of the microwire were measured down to an absolute value of 10−4 in an 8 × 14 µm projected area of the wire. With a beam-defined spatial resolution of 150 × 150 nm, the measurement time was merely 2.5 h.


Author(s):  
A. E. Gunnæs ◽  
A. Olsen ◽  
P. T. Zagierski ◽  
B. Klewe ◽  
O. B. Karlsen ◽  
...  

AbstractThe crystal structure of


Author(s):  
Sergey Yarmolenko ◽  
Devendra Ray ◽  
Devdas Pai ◽  
Jag Sankar

Phase transitions and CTE of 10mol%Sc2O3-1mol%CeO2-ZrO2 ceramics sintered from two commercial powders produced by Praxair Surface Technologies, USA and DKKK, Japan are studied. Morphology of powders and grain structure of ceramics were studied by SEM and AFM. Ceramics produced from Praxair powder exist in cubic phase while DKKK-based ceramics exhibit slow phase transformation from cubic to rhombohedral (β) phase at temperatures 350–400°C. c-β Phase transition temperature is 440°C obtained by high temperature x-ray diffractometry (HTXRD) and differential scanning calorimetry. Coefficients of thermal expansion of cubic and β-phases were calculated from temperature dependence of lattice parameters obtained by HTXRD in the temperature range of 25–800°C. These results can be further used for the optimal design of SOFC layered structures as well as for determination of their reliability and durability under operational conditions.


Author(s):  
E. Louise R. Robins ◽  
Michela Brunelli ◽  
Asiloé J. Mora ◽  
Andrew N. Fitch

AbstractDSC and high-resolution powder X-ray diffraction measurements in the range 295 K–100 K show that RS-thiocamphor undergoes two phase transitions. The first, at around 260 K on cooling, is from the room-temperature body-centred-cubic phase to a short-lived intermediate. At 258 K the low-temperature form starts to appear. The crystal structure of the latter is orthorhombic, space group


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