ANOMALIES OF CELL PARAMETERS BEFORE SUPERCONDUCTING TRANSITION FOR BISMUTH BASED OXIDE SUPERCONDUCTOR

1989 ◽  
Vol 03 (09) ◽  
pp. 685-693 ◽  
Author(s):  
S.L. YUAN ◽  
W.Y. GUAN ◽  
Z.J. CHEN ◽  
Y.L. HUANG ◽  
Y.B. JIA ◽  
...  
Keyword(s):  
Phase Transition ◽  
Diffraction Analysis ◽  
Low Temperatures ◽  
Structural Phase ◽  
Oxide Superconductors ◽  
Superconducting Transition ◽  
Oxide Superconductor ◽  
X Ray Diffraction ◽  
X Ray ◽  
Cell Parameters

The results of X-ray diffraction analysis at low temperatures for bismuth-based high-Tc oxide superconductors are reported in this letter. There is no significant structural phase transition during superconducting transition. However, it appears that the cell parameters change anomalously before superconducting transition. This anomalous change in cell parameters is repeated for different bismuth-based high-Tc oxide superconductors.

X-ray diffraction and Raman study of DL-alanine at high pressure: revision of phase transitions

2012 ◽  
Vol 68 (4) ◽  
pp. 412-423 ◽  
Author(s):  
Nikolay A. Tumanov ◽  
Elena V. Boldyreva
Keyword(s):  
Phase Transition ◽  
Phase Transitions ◽  
Structural Phase ◽  
Group Symmetry ◽  
Second Phase ◽  
Structural Phase Transitions ◽  
X Ray Diffraction ◽  
X Ray ◽  
Cell Parameters ◽  
Raman Study

The effect of pressure on DL-alanine has been studied by X-ray powder diffraction (up to 8.3 GPa), single-crystal X-ray diffraction and Raman spectroscopy (up to ∼ 6 GPa). No structural phase transitions have been observed. At ∼ 1.5–2 GPa, cell parameters b and c become accidentally equal to each other, but the space-group symmetry does not change. There is no phase transition between 1.7 and 2.3 GPa, contrary to what has been reported earlier [Belo et al. (2010). Vibr. Spectrosc. 54, 107–111]. The presence of the second phase transition, which was claimed to appear within the pressure range from 6.0 to 7.3 GPa (Belo et al., 2010), is also argued. The changes in the Raman spectra have been shown to be continuous in all the pressure ranges studied.

scholarly journals Cloning, expression, purification, crystallization and preliminary X-ray diffraction analysis of AerF fromMicrocystis aeruginosa, a putative reductase participating in aeruginosin biosynthesis

2015 ◽  
Vol 71 (4) ◽  
pp. 466-470 ◽  
Author(s):  
Ruyi Ding ◽  
Cui Xu ◽  
Xu Chen ◽  
Mengyun Bao ◽  
Xiaoting Qiu
Keyword(s):  
Diffraction Analysis ◽  
Biosynthetic Pathway ◽  
Molecular Replacement ◽  
X Ray Diffraction ◽  
Antithrombotic Activity ◽  
X Ray ◽  
Cell Parameters ◽  
Maximum Resolution ◽  
Replacement Method ◽  
Molecular Replacement Method

The 2-carboxy-6-hydroxyoctahydroindole moiety is an essential residue for the antithrombotic activity of aeruginosins, which are a class of cyanobacteria-derived bioactive linear tetrapeptides. The biosynthetic pathway of the 2-carboxy-6-hydroxyoctahydroindole moiety has not yet been resolved. AerF was indicated to be involved in the biosynthesis of the 2-carboxy-6-hydroxyoctahydroindole moiety. This study reports the cloning, expression, purification, crystallization and preliminary X-ray diffraction analysis of AerF fromMicrocystis aeruginosawith a C-terminal His6tag. The crystal diffracted to a maximum resolution of 1.38 Å and belonged to the tetragonal space groupP4322, with unit-cell parametersa=b= 101.581,c= 116.094 Å. The calculated Matthews coefficient and solvent content of the crystal were 2.47 Å3 Da−1and 50.32%, respectively. The initial model of the structure was obtained by the molecular-replacement method and refinement of the structure is in progress.

Structural-phase transition in (Cu2Te)2−x(ZnTe)x at high temperature

2021 ◽  
pp. 2150113
Author(s):  
H. B. Gasimov ◽  
R. M. Rzayev
Keyword(s):  
Phase Transition ◽  
Phase Transitions ◽  
High Temperature ◽  
Single Crystals ◽  
Structural Phase ◽  
X Ray Diffraction ◽  
X Ray ◽  
Temperature Range ◽  
Xrd Study ◽  
Xrd Method

Cu2Te single crystal was grown by the Bridgman method. X-ray diffraction (XRD) study of Cu2Te single crystals in the temperature range of 293–893 K was performed and possible phase transitions in the mentioned range of temperature have been investigated. (Cu2Te)[Formula: see text](ZnTe)[Formula: see text] single crystals also were grown with [Formula: see text], 0.05, 0.10 concentrations and structural properties of the obtained single crystals were investigated by the XRD method in the temperature range 293–893 K. Lattice parameters and possible phase transitions in the mention temperature range were determined for (Cu2Te)[Formula: see text](ZnTe)[Formula: see text] single crystals for [Formula: see text], 0.05, 0.10 concentrations.

scholarly journals Purification, crystallization and preliminary X-ray diffraction analysis of Imp3 in complex with an Mpp10 peptide involved in yeast ribosome biogenesis

2014 ◽  
Vol 70 (7) ◽  
pp. 918-921 ◽  
Author(s):  
Sanduo Zheng ◽  
Keqiong Ye
Keyword(s):  
Diffraction Analysis ◽  
Associated Factors ◽  
Ribosome Biogenesis ◽  
X Ray Diffraction ◽  
Unit Cell Parameters ◽  
Vast Number ◽  
X Ray ◽  
Cell Parameters ◽  
Early Processing ◽  
Ribosomal Particle

Eukaryotic ribosome synthesis requires a vast number of transiently associated factors. Mpp10, Imp3 and Imp4 form a protein complex in the 90S pre-ribosomal particle that conducts early processing of 18S rRNA. Here, a short fragment of Mpp10 was identified to associate with and increase the solubility of Imp3. An Imp3–Mpp10 complex was co-expressed, co-purified and co-crystallized. Preliminary X-ray diffraction analysis revealed that the crystal diffracted to 2.1 Å resolution and belonged to space groupP212121, with unit-cell parametersa= 51.6,b= 86.9,c= 88.7 Å.

Synthesis, growth, structure and characterization of molybdenum zinc thiourea complex crystals

2015 ◽  
Vol 71 (3) ◽  
pp. 285-292 ◽  
Author(s):  
M. Rajasekar ◽  
K. Muthu ◽  
A. Aditya Prasad ◽  
R. Agilandeshwari ◽  
SP Meenakshisundaram
Keyword(s):  
Single Crystal ◽  
Diffraction Analysis ◽  
Intermolecular Interactions ◽  
Crystal Packing ◽  
Second Harmonic ◽  
Morphological Changes ◽  
Strong Interactions ◽  
X Ray Diffraction ◽  
X Ray ◽  
Cell Parameters

Single crystals of molybdenum-incorporated tris(thiourea)zinc(II) sulfate (MoZTS) are grown by the slow evaporation solution growth technique. Crystal composition as determined by single-crystal X-ray diffraction analysis reveals that it belongs to the orthorhombic system with space groupPca21and cell parametersa= 11.153 (2),b= 7.7691 (14),c= 15.408 (3) Å,V= 1335.14 (4) Å3andZ= 4. The surface morphological changes are studied by scanning electron microscopy. The vibrational patterns in FT–IR are used to identify the functional group and TGA/DTA (thermogravimetric analysis/differential thermal analysis) indicates the stability of the material. The structure and the crystallinity of the material were confirmed by powder X-ray diffraction analysis and the simulated X-ray diffraction (XRD) closely matches the experimental one with varied intensity patterns. The band gap energy is estimated using diffuse reflectance data by the application of the Kubelka–Munk algorithm. The relative second harmonic generation (SHG) efficiency measurements reveal that MoZTS has an efficiency comparable to that of tris(thiourea)zinc(II) sulfate (ZTS). Hirshfeld surfaces were derived using single-crystal X-ray diffraction data. Investigation of the intermolecular interactions and crystal packingviaHirshfeld surface analysis reveal that the close contacts are associated with strong interactions. Intermolecular interactions as revealed by the fingerprint plot and close packing could be the possible reasons for facile charge transfer leading to SHG activity.

Structure and properties of solid solutions in the Mg-Al-B system

Open Physics ◽  
2012 ◽  
Vol 10 (1) ◽  
Author(s):  
Ludmila Sevastyanova ◽  
Olga Gulish ◽  
Vladimir Stupnikov ◽  
Vladimir Genchel ◽  
Oleg Kravchenko ◽  
...  
Keyword(s):  
Solid Solutions ◽  
Unit Cell ◽  
Superconducting Transition ◽  
Structure And Properties ◽  
X Ray Diffraction ◽  
Unit Cell Parameters ◽  
X Ray ◽  
Cell Parameters ◽  
Resistivity Measurements ◽  
Ceramic Synthesis

AbstractCompounds with the general formula Mg1−x AlxB2 were obtained by two-step ceramic synthesis. All compounds were characterized by X-ray diffraction, NMR spectroscopy, and by four point probe resistivity measurements in various magnetic fields method. The diborides unit cell parameters were determined as a function of the Al mole fraction. With the vaues of x up to 0.40 (where x is the composition of the stock prepared for sintering), the unit cell parameters of Mg1−x AlxB2 are similar to those of pure MgB2 and the superconducting transition temperature was lowered. For stock compositions of 0:25 ≤ x ≤ 0:60, the products contain a superstructure, also superconducting phase, which becomes the only product at x = 0:50, and at x > 0:60 this phase is replaced by AlB2-based solid solutions.

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