scholarly journals Raman Spectrum of Rubidium Thiocyanate at 37 K and Room Temperature

1989 ◽  
Vol 42 (4) ◽  
pp. 389 ◽  
Author(s):  
MJ Joyce ◽  
F Ninio
Keyword(s):  
Raman Spectrum ◽  
Low Temperature ◽  
Single Crystal ◽  
Room Temperature ◽  
Temperature Data ◽  
Phonon Modes ◽  
New Classification ◽  
External Mode ◽  
Recent Interpretation

The single crystal Raman spectrum of RbSCN from 0 to 2200 cm-l was studied between 37 K and room temperature. A new eak was observed in the B2g polarisation and is believed to be an external mode. The low temperature data indicate that previous interpretations of the external modes are in error. A new classification of these modes is given. Further, whereas the internal modes are in agreement with previous studies, some multi phonon modes are not. The assumed isomorphism between bSCN and KSCN suggests a correction to the most recent interpretation of the spectrum

scholarly journals Symmetrical Analysis Phonon Modes of Crystal -Ag8SnSe6

2015 ◽  
Vol 16 (2) ◽  
pp. 257-260
Author(s):  
І.V. Semkiv ◽  
А.І. Kashuba ◽  
H.A. Ilchuk ◽  
M.V. Chekaylo
Keyword(s):  
Raman Spectra ◽  
Infrared Spectra ◽  
Room Temperature ◽  
Group Symmetry ◽  
Phonon Modes ◽  
Orthorhombic System ◽  
Space Group Symmetry ◽  
Space Group ◽  
Phonon Spectra

Symmetrical analysis of the phonon spectra of  lowtemperature b¢-phase of crystal Ag8SnSe6 carried out. At the room temperature argyrodite Ag8SnSe6 belong to orthorhombic system with space group symmetry Pmn21. Classification of the main phonon modes of crystal carried out. Clarified selection rules for Raman spectra and infrared spectra.

Structural Systematics of Rare Earth Complexes. XXII. ('Maximally') Hydrated Rare Earth Iodides

2000 ◽  
Vol 53 (10) ◽  
pp. 867 ◽  
Author(s):  
Kevin C. Lim ◽  
Brian W. Skelton ◽  
Allan H. White
Keyword(s):  
Aqueous Solution ◽  
Rare Earth ◽  
Low Temperature ◽  
Single Crystal ◽  
Room Temperature ◽  
Second Phase ◽  
X Ray ◽  
Structure Determinations ◽  
Trivalent Rare Earth ◽  
Trigonal Prismatic

Low-temperature (c. 153 K) single-crystal X-ray structure determinations, carried out on trivalent rare earth iodides crystallized from aqueous solution at room temperature, have defined two series of hydrates, LnI3.nH2O. For Ln = La–Ho, a nonahydrate phase (n = 9) is defined, orthorhombic Pmmn, a ~ 11.5, b ~ 8.0, c ~ 8.8 Å, Z = 2, the second phase (n = 10), monoclinic P21/c, Z = 4 being defined for Ln = Er–Lu, a ~ 8.2, b ~ 12.8, c ~ 17.1 Å, β ~ 103.7˚. Neither of these phases is isomorphous with any of those pertinent to the previously studied chloride or bromide (hydrated) arrays, nor, unlike those, does the halide (iodide) in any case enter the coordination sphere of the lanthanoid. The n = 9 phase takes the form [Ln(OH2)9]I3, the nine-coordinate lanthanoid environment stereochemistry being tricapped trigonal-prismatic, while the n = 10 phase is [Ln(OH2)8]I3.2H2O, the eight-coordinate lanthanoid environment being square-antiprismatic.

Low temperature transformations and twinning in La2-xSrxCuO4-δ and La2CuO4

1988 ◽  
Vol 46 ◽  
pp. 854-855
Author(s):  
T. Roy ◽  
T. E. Mitchell
Keyword(s):  
Low Temperature ◽  
Single Crystal ◽  
Perovskite Structure ◽  
Room Temperature ◽  
Unit Cell ◽  
Orthorhombic Unit Cell ◽  
Ceramic Superconductors ◽  
Tetragonal Unit Cell ◽  
Structure And Microstructure

Electron microscopists have played an important role in structure and microstructure determinations of ceramic superconductors ever since their discovery. Most of the work has been done on the 123 compounds. In the present investigation, we have used conventional TEM techniques at various temperatures to study the tetragonal to orthorhombic transformation in 214 compounds.Single crystal La2CuO4 and polycrystalline La2-xSrxCuO4-δ (x∼0.15) were used in this investigation. La2CuO4 crystals were grown from a PbO flux and polycrystalline La2-xSrxCuO4-δ was made from stoichiometric mixtures of La2O3, CuO and SrO in the usual way. The results reported here were obtained from bulk ion-milled samples. Microscopy was performed using a Philips EM400T operating at 120kV, sometimes using a Gatan specimen cooler.Both compounds have a triple perovskite structure. At room temperature, La2-xSrxCuO4-δ has a tetragonal unit cell (ao=3.775 A, co=13.223 A) while La2CuO4 has an orthorhombic unit cell (ao=5.363 A, bo=5.403 A, co=13.17 A).

Low-temperature raman study on ThSiO4 single crystal and related infrared spectra at room temperature

1986 ◽  
Vol 64 (2) ◽  
pp. 181-187 ◽  
Author(s):  
M.P. Lahalle ◽  
J.C. Krupa ◽  
M. Lepostollec ◽  
J.P. Forgerit
Keyword(s):  
Low Temperature ◽  
Single Crystal ◽  
Infrared Spectra ◽  
Room Temperature ◽  
Raman Study

scholarly journals Crystal structure of apatite type Ca2.49Nd7.51(SiO4)6O1.75

2016 ◽  
Vol 72 (2) ◽  
pp. 209-211 ◽  
Author(s):  
Thu Hoai Le ◽  
Neil R. Brooks ◽  
Koen Binnemans ◽  
Bart Blanpain ◽  
Muxing Guo ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Single Crystal ◽  
Room Temperature ◽  
Solubility Limit ◽  
Temperature Data ◽  
X Ray Diffraction ◽  
Slow Cooling ◽  
X Ray ◽  
Natural Apatite ◽  
Apatite Type

The title compound, Ca2+xNd8–x(SiO4)6O2–0.5x(x= 0.49), was synthesized at 1873 K and rapidly quenched to room temperature. Its structure has been determined using single-crystal X-ray diffraction and compared with results reported using neutron and X-ray powder diffraction from samples prepared by slow cooling. The single-crystal structure from room temperature data was found to belong to the space groupP63/mand has the composition Ca2.49Nd7.51(SiO4)6O1.75[dicalcium octaneodymium hexakis(orthosilicate) dioxide], being isotypic with natural apatite and the previously reported Ca2Nd8(SiO4)6O2and Ca2.2Nd7.8(SiO4)6O1.9. The solubility limit of calcium in the equilibrium state at 1873 K was found to occur at a composition of Ca2+xNd8–x(SiO4)6O2–0.5x, wherex= 0.49.

Low-temperature single-crystal Raman spectrum of pyrope

2000 ◽  
Vol 27 (9) ◽  
pp. 645-649 ◽  
Author(s):  
B. A. Kolesov ◽  
C. A. Geiger
Keyword(s):  
Raman Spectrum ◽  
Low Temperature ◽  
Single Crystal

scholarly journals A redetermination of the structure and Hirshfeld surface analysis of poly[diaquadi-μ-hydroxido-tetrakis(μ-nicotinato N-oxide)tricopper(II)]

2021 ◽  
Vol 77 (3) ◽  
pp. 309-313
Author(s):  
Masoud Mirzaei ◽  
Maryam Bazargan ◽  
Pouria Ebtehaj ◽  
Joel T. Mague
Keyword(s):  
Low Temperature ◽  
Dicarboxylic Acid ◽  
Surface Analysis ◽  
Room Temperature ◽  
Temperature Data ◽  
Hirshfeld Surface ◽  
Hirshfeld Surface Analysis ◽  
X Ray Diffraction ◽  
X Ray ◽  
Naoh Solution

The product obtained from the reaction of pyridine-2,3-dicarboxylic acid and hydrated copper(II) chloride in hot aqueous NaOH solution was determined by low temperature X-ray diffraction to be [Cu3(C6H4NO3)4(OH)2(H2O)2] n or [Cu3(μ-OH)2(μ-nicNO)4(H2O)2] n (nicNO is pyridine-3-carboxylate N-oxide), a structure obtained from room temperature data and reported previously. The present determination is improved in quality and treatment of the H atoms. A Hirshfeld surface analysis of the intermolecular interactions is presented.

scholarly journals Methylcyclopentane

2006 ◽  
Vol 62 (4) ◽  
pp. o1211-o1212 ◽  
Author(s):  
Richard Bream ◽  
David Watkin ◽  
Andrew Cowley
Keyword(s):  
Low Temperature ◽  
Single Crystal ◽  
Room Temperature ◽  
Methyl Substituent ◽  
Envelope Conformation ◽  
Computer Controlled

Methylcyclopentane, C6H12, a liquid at room temperature, was studied as part of a project to develop a computer-controlled low-temperature crystal-growing device. A single crystal was obtained at 115 K. The ring has an envelope conformation, with a pseudo-equatorial methyl substituent on the flap atom.

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