Application of X-ray diffraction topography for the study of Al single crystals plastically deformed at low temperatures

1975 ◽  
Vol 10 (3) ◽  
pp. 275-283 ◽  
Author(s):  
I. G. Novikova ◽  
V. I. Startsev ◽  
D. A. Didenko
Keyword(s):  
Single Crystals ◽  
Low Temperatures ◽  
X Ray Diffraction ◽  
X Ray

scholarly journals The Stability of Icosahedral Cd-Yb

2003 ◽  
Vol 805 ◽  
Author(s):  
Günter Krauss ◽  
Sofia Deloudi ◽  
Andrea Steiner ◽  
Walter Steurer ◽  
Amy R. Ross ◽  
...  
Keyword(s):  
Low Temperature ◽  
Ambient Temperature ◽  
Mechanical Stress ◽  
Single Crystals ◽  
High Temperatures ◽  
Low Temperatures ◽  
Ambient Pressure ◽  
X Ray Diffraction ◽  
X Ray ◽  
The Stability

ABSTRACTThe stability of single-crystalline icosahedral Cd-Yb was investigated using X-ray diffraction methods in the temperature range 20 K ≤ T ≤ 900 K at ambient pressure and from ambient temperature to 873 K at about 9 GPa. Single-crystals remain stable at low temperatures and in the investigated HP-HT-regime. At high temperatures and ambient pressure, the quasicrystal decomposes. The application of mechanical stress at low temperatures yields to the same decomposition, the formation of Cd. A reaction of icosahedral Cd-Yb with traces of oxygen or water causing the decomposition seems reasonable, but a low-temperature instability of this binary quasi-crystal cannot be ruled out totally.

Chemistry of the S=O bond. 13. Structures of isomers 1 (I) and 2 (II) of 4-methyl-1,3,2-dioxathiane 2-oxide and 1,3,2-dioxathiepane 2-oxide (III) at 256, 240 and 228 K

1996 ◽  
Vol 52 (3) ◽  
pp. 505-508 ◽  
Author(s):  
D.G. Hellier ◽  
P. Luger ◽  
J. Buschmann
Keyword(s):  
Single Crystals ◽  
Low Temperatures ◽  
Chair Conformation ◽  
Equatorial Position ◽  
X Ray Diffraction ◽  
Compound I ◽  
Methyl Group ◽  
X Ray ◽  
Compound Ii ◽  
Axis Passing

The structures of the two isomers of 4-methyl-1,3,2-dioxathiane 2-oxide, C4H8SO3 (I, II), and 1,3,2-dioxathiepane 2-oxide, C4H8SO3 (III), have been determined by X-ray diffraction methods for single crystals that were grown in this case at low temperatures from the normally liquid compounds. Compound (I): orthorhombic, P212121, Mr = 136.17, a = 7.204 (6), b = 13.670 (11), c = 6.041 (6) Å, V = 594.91 Å3, Z= 4, Dx = 1.520 Mg m−3, Mo Kα (λ = 0.71068 Å), μ = 4.49 cm−1, F(000) = 288, T = 256 K, R = 0.042 for 778 unique reflections. Compound (II): orthorhombic, P212121, Mr = 136.17, a = 18.238 (6), b = 10.265 (3), c = 6.616 (2) Å, V = 1238.60 Å3, Z= 8, Dx = 1.460 Mg m−3, Mo Kα (λ = 0.71068 Å), μ = 4.31 cm−1, F(000) = 576, T = 240 K, R = 0.032 for 1597 unique reflections. Compound (III): monoclinic, P21/n, Mr = 136.17, a = 6.060 (3), b = 11.185 (8), c = 9.186 (4) Å, β = 101.32 (4)°, V = 610.52 Å3, Z = 4, Dx = 1.481 Mg m−3, Mo Kα (λ = 0.71068 Å), μ = 4.38 cm−1, F(000) = 288, T = 228 K, R = 0.037 for 1161 unique reflections. Compound (I) adopts a chair structure, which has a methyl group in an equatorial position and an axially oriented S=O group. Compound (II) is similar, except that the S=O group is equatorially oriented. Compound (III) adopts a twist-chair conformation with a local approximate endocyclic twofold axis passing through S(1) and the middle of the opposite bond, C(4)—C(5).

The Crystal Structures of Chlorodimethyl( dimethylamino)silane and Dimethyl-bis-(dimethylamino)silane

2003 ◽  
Vol 58 (7) ◽  
pp. 708-710 ◽  
Author(s):  
Norbert W. Mitzel ◽  
Krunoslav Vojinović
Keyword(s):  
Single Crystals ◽  
Crystal Structures ◽  
Low Temperatures ◽  
Structural Parameters ◽  
X Ray Diffraction ◽  
X Ray

Single crystals of chlorodimethyl(dimethylamino)silane, Me2NSiMe2Cl, and dimethyl-bis-(dimethylamino)silane, (Me2N)2SiMe2, have been grown in situ from the melt at low temperatures and their structures determined by X-ray diffraction. Important structural parameters (Å / °): Me2NSiMe2Cl (C2/m) Si-N 1.686(2), Si-C 1.851(1), Si- Cl 2.109(1), N-Si-Cl 111.7(1), C-Si-Cl 105.1(1), C-N-C 112.8(2), Si-N-C 123.4(1); (Me2N)2SiMe2 (P21/c) Si-N(1) 1.725(1), Si-C(1) 1.868(1), N(1)-Si-N(2) 105.7(1), C(3)- N(1)-C(4) 111.6(1), Si-N(1)-C(3) 122.4(1), Si-N(1)-C(4) 120.0(1).

Low temperature amorphization and superconductivity in FeSe single crystals at high pressures

2010 ◽  
Vol 25 (2) ◽  
pp. 396-400 ◽  
Author(s):  
Andrew K. Stemshorn ◽  
Georgiy Tsoi ◽  
Yogesh K. Vohra ◽  
Stanislav Sinogeiken ◽  
Phillip M. Wu ◽  
...  
Keyword(s):  
High Pressure ◽  
Low Temperature ◽  
Single Crystals ◽  
Amorphous Phase ◽  
Tetragonal Phase ◽  
Electrical Resistance ◽  
Low Temperatures ◽  
High Pressures ◽  
X Ray Diffraction ◽  
X Ray

In this study, we report low temperature x-ray diffraction studies combined with electrical resistance measurements on single crystals of iron-based layered superconductor FeSe to a temperature of 10 K and a pressure of 44 GPa. The low temperature high pressure x-ray diffraction studies were performed using a synchrotron source and superconductivity at high pressure was studied using designer diamond anvils. At ambient temperature, the FeSe sample shows a phase transformation from a PbO-type tetragonal phase to a NiAs-type hexagonal phase at 10 ± 2 GPa. On cooling, a structural distortion from a PbO-type tetragonal phase to an orthorhombic Cmma phase is observed below 100 K. At a low temperature of 10 K, compression of the orthorhombic Cmma phase results in a gradual transformation to an amorphous phase above 15 GPa. The transformation to the amorphous phase is completed by 40 GPa at 10 K. A loss of superconductivity is observed in the amorphous phase and a dramatic change in the temperature behavior of electrical resistance indicates formation of a semiconducting state at high pressures and low temperatures. The formation of the amorphous phase is attributed to a kinetic hindrance to the growth of a hexagonal NiAs phase under high pressures and low temperatures.

Effect of trytophan as dopant on potassium acid phthalate single crystals

2019 ◽  
Author(s):  
Chem Int
Keyword(s):  
Single Crystals ◽  
Room Temperature ◽  
Visible Region ◽  
X Ray Diffraction ◽  
X Ray ◽  
Slow Evaporation Technique ◽  
Absorption Studies ◽  
Evaporation Technique ◽  
Potassium Acid Phthalate ◽  
Acid Phthalate

Optically transparent single crystals of potassium acid phthalate (KAP, 0.5 g) 0.05 g and 0.1 g (1 and 2 mol %) trytophan were grown in aqueous solution by slow evaporation technique at room temperature. Single crystal X- ray diffraction analysis confirmed the changes in the lattice parameters of the doped crystals. The presence of functional groups in the crystal lattice has been determined qualitatively by FTIR analysis. Optical absorption studies revealed that the doped crystals possess very low absorption in the entire visible region. The dielectric constant has been studied as a function of frequency for the doped crystals. The thermal stability was evaluated by TG-DSC analysis.

scholarly journals Some Novel Cobalt Diphenylphosphine Complexes: Synthesis, Characterization, and Behavior in the Polymerization of 1,3-Butadiene

Molecules ◽  
2021 ◽  
Vol 26 (13) ◽  
pp. 4067
Author(s):  
Giovanni Ricci ◽  
Giuseppe Leone ◽  
Giorgia Zanchin ◽  
Benedetta Palucci ◽  
Alessandra Forni ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Single Crystals ◽  
The Novel ◽  
X Ray Diffraction ◽  
X Ray ◽  
And Behavior

Some novel cobalt diphenylphosphine complexes were synthesized by reacting cobalt(II) chloride with (2-methoxyethyl)diphenylphosphine, (2-methoxyphenyl)diphenylphosphine, and 2-(1,1-dimethylpropyl)-6-(diphenylphosphino)pyridine. Single crystals suitable for X-ray diffraction studies were obtained for the first two complexes, and their crystal structure was determined. The novel compounds were then used in association with methylaluminoxane (MAO) for the polymerization of 1,3-butadiene, and their behavior was compared with that exhibited in the polymerization of the same monomer by the systems CoCl2(PnPrPh2)2/MAO and CoCl2(PPh3)2/MAO. Some significant differences were observed depending on the MAO/Co ratio used, and a plausible interpretation for such a different behavior is proposed.

scholarly journals Growth of sillenite Bi12FeO20 single crystals: structural, thermal, optical, photocatalytic features and first principle calculations

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Durga Sankar Vavilapalli ◽  
Ambrose A. Melvin ◽  
F. Bellarmine ◽  
Ramanjaneyulu Mannam ◽  
Srihari Velaga ◽  
...  
Keyword(s):  
Single Crystal ◽  
Single Crystals ◽  
Photoelectron Spectroscopy ◽  
Diffraction Method ◽  
Lattice Parameter ◽  
First Principle ◽  
X Ray Diffraction ◽  
X Ray ◽  
First Principle Calculations ◽  
Photodegradation Efficiency

AbstractIdeal sillenite type Bi12FeO20 (BFO) micron sized single crystals have been successfully grown via inexpensive hydrothermal method. The refined single crystal X-ray diffraction data reveals cubic Bi12FeO20 structure with single crystal parameters. Occurrence of rare Fe4+ state is identified via X-ray photoelectron spectroscopy (XPS) and X-ray absorption spectroscopy (XAS). The lattice parameter (a) and corresponding molar volume (Vm) of Bi12FeO20 have been measured in the temperature range of 30–700 °C by the X-ray diffraction method. The thermal expansion coefficient (α) 3.93 × 10–5 K−1 was calculated from the measured values of the parameters. Electronic structure and density of states are investigated by first principle calculations. Photoelectrochemical measurements on single crystals with bandgap of 2 eV reveal significant photo response. The photoactivity of as grown crystals were further investigated by degrading organic effluents such as Methylene blue (MB) and Congo red (CR) under natural sunlight. BFO showed photodegradation efficiency about 74.23% and 32.10% for degrading MB and CR respectively. Interesting morphology and microstructure of pointed spearhead like BFO crystals provide a new insight in designing and synthesizing multifunctional single crystals.

scholarly journals Modeling of magneto-conductivity of bismuth selenide: a topological insulator

2021 ◽  
Vol 3 (4) ◽  
Author(s):  
Yogesh Kumar ◽  
Rabia Sultana ◽  
Prince Sharma ◽  
V. P. S. Awana
Keyword(s):  
Magnetic Field ◽  
Magnetic Fields ◽  
Single Crystal ◽  
Single Crystals ◽  
X Ray Diffraction ◽  
Field Range ◽  
X Ray ◽  
Bulk Carriers ◽  
Different Temperatures

AbstractWe report the magneto-conductivity analysis of Bi2Se3 single crystal at different temperatures in a magnetic field range of ± 14 T. The single crystals are grown by the self-flux method and characterized through X-ray diffraction, Scanning Electron Microscopy, and Raman Spectroscopy. The single crystals show magnetoresistance (MR%) of around 380% at a magnetic field of 14 T and a temperature of 5 K. The Hikami–Larkin–Nagaoka (HLN) equation has been used to fit the magneto-conductivity (MC) data. However, the HLN fitted curve deviates at higher magnetic fields above 1 T, suggesting that the role of surface-driven conductivity suppresses with an increasing magnetic field. This article proposes a speculative model comprising of surface-driven HLN and added quantum diffusive and bulk carriers-driven classical terms. The model successfully explains the MC of the Bi2Se3 single crystal at various temperatures (5–200 K) and applied magnetic fields (up to 14 T).

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