scholarly journals Low-Temperature Crystal Structure and Mean-Field Modeling of ErxDy1−xAl2 Intermetallics

Metals ◽  
2020 ◽  
Vol 10 (12) ◽  
pp. 1662
Author(s):  
Yaroslav Mudryk ◽  
Bruno P. Alho ◽  
Paula O. Ribeiro ◽  
Vitalij K. Pecharsky
Keyword(s):  
Crystal Structure ◽  
Low Temperature ◽  
Mean Field Theory ◽  
Mean Field ◽  
Magnetic Ordering ◽  
X Ray Diffraction ◽  
Easy Magnetization ◽  
Rhombohedral Distortion ◽  
Magnetization Axis ◽  
Low Temperature Crystal Structure

Low-temperature crystal structure of the ErxDy1−xAl2 alloys with x = 0.45, 0.67, 0.90 was examined using temperature-dependent powder X-ray diffraction. The Er-rich sample, Er0.9Dy0.1Al2, exhibits a rhombohedral distortion associated with the magnetic ordering that occurs around 20 K. The rhombohedral distortion is suppressed in Er0.67Dy0.33Al2, while a weak low-temperature tetragonal distortion is observed in Er0.45Dy0.55Al2. The mean-field theory supports the correlation between the type of structural distortion and the variable easy magnetization axis in ErxDy1−xAl2 intermetallics.

Low-temperature crystal structure of RS-thiocamphor

2004 ◽  
Vol 219 (9) ◽  
Author(s):  
E. Louise R. Robins ◽  
Michela Brunelli ◽  
Asiloé J. Mora ◽  
Andrew N. Fitch
Keyword(s):  
Crystal Structure ◽  
Phase Transitions ◽  
Low Temperature ◽  
Room Temperature ◽  
Cubic Phase ◽  
X Ray Diffraction ◽  
Orthorhombic Space Group ◽  
Two Phase ◽  
X Ray ◽  
Low Temperature Crystal Structure

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

Low-temperature Crystal Structure and 57Fe Mössbauer Spectroscopy of Sr3Sc2O5Fe2As2

2009 ◽  
Vol 64 (7) ◽  
pp. 815-820 ◽  
Author(s):  
Marcus Tegela ◽  
Inga Schellenberg ◽  
Franziska Hummel ◽  
Rainer Pöttgen ◽  
Dirk Jorendt
Keyword(s):  
Crystal Structure ◽  
Low Temperature ◽  
Isomer Shift ◽  
Quadrupole Splitting ◽  
Spectroscopic Data ◽  
Bond Angle ◽  
Magnetic Ordering ◽  
Structural Instability ◽  
Low Temperature Crystal Structure ◽  
Tetragonal Cell

The crystal structure of the layered iron arsenide Sr3Sc2O5Fe2As2 was determined between 300 and 10 K. The lattice parameters of the tetragonal cell decrease anisotropically according to Δc/c : Δa/a ≈ 4.2, which results in a slight flattening of the As-Fe-As bond angle within the FeAs layers. No indication of a structural instability could be detected. 57Fe Mössbauer spectroscopic data show only a single signal at 4.2, 77, and 298 K, subjected to quadrupole splitting. The isomer shift increases from 0.36(1) mms−1 at 298 K to 0.49(1) mms−1 at 4.2 K. No indication for magnetic ordering was found.

Thermally Induced Symmetry and Disorder: The Low-Temperature Crystal Structure of Diaquadichlorodimethyltin · 15-crown-5

1996 ◽  
Vol 1 (3) ◽  
pp. 359-363 ◽  
Author(s):  
Glenn P. A. Yap ◽  
Mostafa M. Amini ◽  
Seik W. Ng ◽  
Anne E. Counterman ◽  
Arnold L. Rheingold
Keyword(s):  
Crystal Structure ◽  
Low Temperature ◽  
Thermally Induced ◽  
Low Temperature Crystal Structure

scholarly journals Synthesis, Crystal Structure and Magnetic Properties of Bixbyite-type Vanadium Oxide Nitrides

2009 ◽  
Vol 64 (3) ◽  
pp. 281-286 ◽  
Author(s):  
Suliman Nakhal ◽  
Wilfried Hermes ◽  
Thorsten Ressler ◽  
Rainer Pöttgen ◽  
Martin Lerch
Keyword(s):  
Crystal Structure ◽  
Vanadium Oxide ◽  
Magnetic Ordering ◽  
Vanadium Oxides ◽  
Detectable Amount ◽  
X Ray Diffraction ◽  
X Ray ◽  
Vanadium Sulfide ◽  
Structure Result ◽  
X Ray Absorption

Ammonolysis of vanadium sulfide leads to the formation of bixbyite-type vanadium oxide nitrides. Small amounts of nitrogen incorporated in the structure result in the stabilization of the bixbyite type not known for vanadium oxides. The crystal structure was investigated using X-ray diffraction and X-ray absorption spectroscopy. At temperatures above 550 °C the powders decompose to corundumtype V2O3 containing no detectable amount of nitrogen. Below 39 K magnetic ordering is observed.

π-Olefin-Iridium-Komplexe, XXII [1]. C-H-Aktivierung von aromatischen und aliphatischen Solvensmolekülen RH bei der Reaktion von [Cp*IrCI2]2 mit Butadienmagnesium unter Bildung von [Cp*Ir(η3-C4H7)R] sowie Kristallstruktur von [Cp*Ir(η3-C4H7)C6H5] / π-Olefin Iridium Complexes, XXII [1]. C-H Activation of Aromatic and Aliphatic Solvent Molecules RH in the Reaction of [Cp*IrCl2]2 with Butadienemagnesium with Formation of [Cp*Ir(η3-C4H7)R], and Crystal Structure of [Cp*Ir(η3-C4H7)C6H5]

1994 ◽  
Vol 49 (12) ◽  
pp. 1645-1653 ◽  
Author(s):  
Jörn Müller ◽  
Petra Escarpa Gaede ◽  
Ke Qiao
Keyword(s):  
Crystal Structure ◽  
Low Temperature ◽  
Diffraction Analysis ◽  
Iridium Complexes ◽  
X Ray Diffraction ◽  
X Ray ◽  
Nmr Spectrometry ◽  
Benzene Toluene ◽  
Solvent Molecules ◽  
Mechanism Of The Reaction

Reactions of [Cp*IrCl2]2 (Cp*=η3-C5Me5) with [MgC4H6·2 THF]n at low temperature give [Cp*Ir(η4-C4H6)] together with [Cp*Ir(η3-C4H7)R] compounds, the latter being formed via C-H activation of solvent molecules RH (RH = benzene, toluene, anisole, thiophene, furane, N-methylpyrrole, pentane, cyclohexane. THF). In the case of pyrrole, C-N -activation occurs. The ratio of syn and anti isomers of the 1-methylallyl complexes as well as the sites of C-H activation of RH were investigated by NMR spectrometry. An enantiomorphous crystal of [Cp*Ir(η3-C4H7)C6Hs] was characterized by X-ray diffraction analysis which reveals trigonal planar coordination at the Ir atom and an exo, syn conformation of the 1-methylallyl ligand. A mechanism of the reaction which involves 16-electron intermediates is discussed. The corresponding system [Cp*RhCl2]2/butadienemagnesium/RH gives only [Cp*Rh(η4-C4H6)], and no C-H activation is observed.

scholarly journals PicW2 fromPicea wilsonii: preparation, purification, crystallization and X-ray diffraction analysis

2018 ◽  
Vol 74 (6) ◽  
pp. 363-366 ◽  
Author(s):  
Bei Zhang ◽  
Gangxing Guo ◽  
Fang Lu ◽  
Ying Song ◽  
Yong Liu ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Low Temperature ◽  
Gel Filtration ◽  
Three Dimensional ◽  
Temperature Tolerance ◽  
Diffusion Method ◽  
Limiting Factor ◽  
X Ray Diffraction ◽  
X Ray ◽  
Cell Parameters

Low temperature is a major limiting factor for plant growth and development. Dehydrin proteins are generally induced in response to low-temperature stress. In previous research, a full-length dehydrin gene,PicW2, was isolated fromPicea wilsoniiand its expression was associated with hardiness to cold. In order to gain insight into the mechanism of low-temperature tolerance by studying its three-dimensional crystal structure, prokaryotically expressed PicW2 dehydrin protein was purified using chitosan-affinity chromatography and gel filtration, and crystallized using the vapour-diffusion method. The crystal grew in a condition consisting of 0.1 MHEPES pH 8.0, 25%(w/v) PEG 3350 using 4 mg ml−1protein solution at 289 K. X-ray diffraction data were collected from a crystal at 100 K to 2.82 Å resolution. The crystal belonged to space groupC121, with unit-cell parametersa= 121.55,b= 33.26,c= 73.39 Å, α = γ = 90.00, β = 109.01°. The asymmetric unit contained one molecule of the protein, with a corresponding Matthews coefficient of 2.87 Å3 Da−1and a solvent content of 57.20%. Owing to a lack of structures of homologous dehydrin proteins, molecular-replacement trials failed. Data collection for selenium derivatization of PicW2 and crystal structure determination is currently in progress.

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