Raman study of the structural properties of KNO3(II)

1977 ◽  
Vol 55 (7) ◽  
pp. 1242-1250 ◽  
Author(s):  
M. H. Brooker
Keyword(s):  
Single Crystals ◽  
Structural Properties ◽  
Raman Spectra ◽  
Excellent Agreement ◽  
Room Temperature ◽  
Group Analysis ◽  
Factor Group ◽  
Spectral Features ◽  
Space Group ◽  
Raman Study

Raman spectra of oriented single crystals of KNO3(II) have been recorded at 298 and 77 K. At both temperatures the data are in excellent agreement with the factor group analysis based on the generally accepted Pmcn space group. Additional spectral features observed near room temperature suggest the presence of a significant number of disordered nitrate groups on alternate lattice sites, although the majority of nitrate groups occupy the ordered sites. As the temperature is lowered, the disordered groups freeze out until near the temperature of reported electrical anomalies (213 K) only the ordered sites are occupied. Improved resolution has resulted in detection of a number of new spectral features while improved depolarization data have resulted in reassignment of several peaks.

Low frequency Raman spectra of the liquid and plastic crystal phases of O2, N2, CO, and of Ar crystals with these molecules as guests

1982 ◽  
Vol 60 (9) ◽  
pp. 1358-1364 ◽  
Author(s):  
N. H. Rich ◽  
M. J. Clouter ◽  
H. Kiefte ◽  
S. F. Ahmad
Keyword(s):  
Single Crystals ◽  
Raman Spectra ◽  
Phonon Mode ◽  
Low Frequency ◽  
Impurity Molecule ◽  
Spectral Features ◽  
Background Impurity ◽  
Crystal Phases ◽  
Distinct Features ◽  
Frequency Feature

Low frequency Raman spectra of single crystals of orientationally disordered phases of oxygen, nitrogen, and carbon monoxide, and spectra of those substances as liquids show two linear segments in semi-log plots. Slopes of the higher frequency segments are nearly equal for all cases; slopes of the lower frequency segments are particular to the substance and are nearly the same in both liquid and crystal for O2 and CO. Spectra of single crystals of argon doped with O2, N2, or CO show two distinct features superimposed on a sloping background. Impurity molecule reorientation apparently accounts satisfactorily for all spectral features, but translation–rotation coupling may allow a contribution to the higher frequency feature arising from a local phonon mode in argon.

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.

scholarly journals Synthesis and Structural Properties of Nanocomposites Based on Synthetic Opals and Active Dielectrics

2019 ◽  
Vol 12 (1) ◽  
pp. 19
Author(s):  
Bilal Abu Sal
Keyword(s):  
Raman Spectroscopy ◽  
Single Crystals ◽  
Structural Properties ◽  
Raman Spectra ◽  
Phase Structure ◽  
Opal Matrix ◽  
X Ray Diffraction ◽  
X Ray ◽  
Crystal State ◽  
Synthetic Opals

This work is devoted to generalize and analyze the previouse results of new photonic-crystalline nanomaterials based on synthetic opals and active dielectrics. Data were characterized by X-ray diffraction and Raman spectroscopy. Active dielectrics infiltrated into the pores of the opal from the melt. The phase structure composition of the infiltrated materials into the pores of the opal matrix were analyzed. The results of x-ray diffraction and Raman spectra allowed to establish the crystal state of active dielectrics in the pores of the opal. The Raman spectra of some opal-active dielectric nanocomposites revealed new bands and changes in band intensities compared to the spectra of single crystals of active dielectrics. Further more, differences in band intensities in the spectra were measured at different spots of the sample‘s surface were observed. The revealed changes were attributed to the formation of new crystalline phases due to the injected dielectrics in opal pores.

Raman study on quenched YBa2Cu3O7−σ single crystals: Evidence of charge transfer during oxygen ordering on room temperature annealing

1991 ◽  
Vol 185-189 ◽  
pp. 827-828 ◽  
Author(s):  
Kiyoto Matsuishi ◽  
Yuan-Kai Tao ◽  
Hung-Su Feng ◽  
Pei-Herng Hor ◽  
Ching-Wu Chu
Keyword(s):  
Charge Transfer ◽  
Single Crystals ◽  
Room Temperature ◽  
Oxygen Ordering ◽  
Raman Study

The Vibrational Spectra and Crystal Structure of Acenaphthylene

1973 ◽  
Vol 51 (3) ◽  
pp. 402-404 ◽  
Author(s):  
A. Bree ◽  
R. A. Kydd ◽  
V. V. B. Vilkos ◽  
R. S. Williams
Keyword(s):  
Crystal Structure ◽  
Single Crystals ◽  
Raman Spectra ◽  
Vibrational Spectra ◽  
Room Temperature ◽  
Infrared And Raman Spectra ◽  
Depolarization Ratio ◽  
X Ray

A study of the polarized infrared and Raman spectra of acenaphthylene single crystals has been made. These results, together with Gordon and Yang's preliminary X-ray work, suggest that the molecules pack in some disordered arrangement in the solid at room temperature. Most of the A1 fundamentals were identified in the Raman solution spectrum from their low depolarization ratio, and a few tentative assignments of nontotally symmetric fundamentals were made.

Raman-Spektren eines AsJ3-Einkristalls und von SbJ3-und BiJ3-Kristallpulvern / Raman spectra of an AsJ3-single crystal and of SbJ3- and BiJ3--crystal powders

1970 ◽  
Vol 25 (7) ◽  
pp. 1101-1107 ◽  
Author(s):  
W. Kiefer
Keyword(s):  
Single Crystal ◽  
Raman Spectra ◽  
Ruby Laser ◽  
Factor Group ◽  
Unit Cell ◽  
Space Group ◽  
Polarization Measurements ◽  
Double Monochromator ◽  
Depolarization Ratios

Raman spectra of an AsJ3-single crystal were recorded using a quasicontinuous ruby laser, a double monochromator and a special registration electronics. The polarization measurements allow the assignments of the internal, translational and rotational modes of AsJ3 (factor group S6). Since SbJ3 and BiJ3 have the same space group and the same number of molecules per unit cell, one can assign the wavenumbers of the crystal powder Raman spectra in analogy to AsJ3. The depolarization ratios of the Raman lines of AsJ3 in solutions were also determined

Die Kristallstruktur von Gadolinium (III)-sulfit Trihydrat Gd2(S03)3∙ 3H2O / Crystal Structure of Gadolinium(III)-sulfite Trihydrate Gd2(SO3)3 ∙3H2O

1994 ◽  
Vol 49 (1) ◽  
pp. 60-62 ◽  
Author(s):  
Hans-Ulrich Hummel ◽  
Petra Joerg ◽  
Gerhard Pezzei ◽  
Alexander Wolski
Keyword(s):  
Crystal Structure ◽  
Single Crystals ◽  
Room Temperature ◽  
Triclinic Space Group ◽  
Space Group ◽  
Bond Lengths ◽  
Clear Solution ◽  
Oxygen Atoms

Abstract Gd2(SO3)3 • 3 H20 is obtained by passing gaseous SO2 through a suspension of Gd2O3 in H2O at room temperature until a clear solution is formed. Single crystals are obtained by heating to 70(2) °C for 6 days. The compound crystallizes in the triclinic space group P 1 with a = 6.499(6), b = 6.621(3), c = 6.954(3) Å, α = 110.71(5), β = 90.54(3), γ = 106.05(1)° and Z = 1. The two crystallographically different gadolinium atoms are both coordinated by eight oxygen atoms forming distorted square antiprisms. Gd(l) is coordinated by six O atoms of sulfite ligands and two O atoms of water, while Gd(2) is surrounded by seven O atoms of SO3 and one of H2O. Gd-O-bond lengths vary between 2.31(3) and 2.50(3) Å.

Orthoborate Halides with the Formula (M+II)5(BO3)3X: Syntheses, Crystal Structures and Raman Spectra of Eu5(BO3)3Cl and Ba5(BO3)3X (X = Cl, Br)

2011 ◽  
Vol 66 (4) ◽  
pp. 359-365 ◽  
Author(s):  
Olaf Reckeweg ◽  
Armin Schulz ◽  
Francis J. DiSalvo
Keyword(s):  
Single Crystal ◽  
Single Crystals ◽  
Crystal Structures ◽  
Raman Spectra ◽  
Direct Synthesis ◽  
X Ray Diffraction ◽  
Orthorhombic Space Group ◽  
Space Group ◽  
X Ray ◽  
Incremental Volume

Single crystals of Eu5(BO3)3Cl were obtained by serendipity by reacting Eu2O3 and Mg with B2O3 at 1300 K in the presence of an NaCl melt for 13 h in silica-jacketed Nb ampoules. Ba5(BO3)3X (X = Cl, Br) crystals were formed by direct synthesis from appropriate amounts of Ba(OH)2, H3BO3 and the respective barium halide (hydrate) in alumina crucibles kept in the open atmosphere at 1300 K for 13 h. The crystal structures of the title compounds were determined with single-crystal X-ray diffraction. All compounds crystallize isotypically to Sr5(BO3)3Cl in the orthorhombic space group C2221 (no. 20, Z = 4) with the lattice parameters a = 1000.34(7), b = 1419.00(9), c = 739.48(5) pm for Eu5(BO3)3Cl, a = 1045.49(5), b = 1487.89(8), c = 787.01(4) pm for Ba5(BO3)3Cl, and a = 1048.76(7), b = 1481.13(9) and c = 801.22(5) pm for Ba5(BO3)3Br. The Raman spectra of all compounds were acquired and are presented and compared to literature data. The incremental volume of the orthoborate (BO3)3− anion has been determined and is compared to the Biltz volume

Identification of two lead perovskites, Pb2ScTaO6 and Pb(Sc0.5Nb0.5)O3, by X-ray powder diffraction patterns

1993 ◽  
Vol 8 (3) ◽  
pp. 191-193 ◽  
Author(s):  
C. Caranoni ◽  
P. Lampin ◽  
C. Boulesteix
Keyword(s):  
Single Crystals ◽  
Powder Diffraction ◽  
Perovskite Structure ◽  
Room Temperature ◽  
Stoichiometric Mixture ◽  
High Quality ◽  
Space Group ◽  
X Ray ◽  
Diffraction Patterns ◽  
Degree Of Order

Substituting cations in materials with the formula Pb2B′B″O6 is more or less ordered on the B sites. High-quality single crystals of Pb2ScTaO6 (PST) and Pb(Sc0.5Nb0.5)O3 (PSN) were prepared from two thermal cycles. A stoichiometric mixture of the constituent oxides was prefired at up to 1000 °C, and then crystals were grown from a PbO–B2O3–PbF2 flux mixture, starting at a temperature of 1100 °C for PSN and 1200 °C for PST. At room temperature, X-ray examination showed that PSN had a perovskite structure with a cubic unit-cell and a refined parameter a = 4.080(1 ) Å, space group Pm3m and Z = 1, whereas PST formed a well-ordered superlattice with a = 8.136(1) Å, Z = 4 and space group Fm3m. In each case a fully indexed powder pattern is presented. The degree of order is estimated to be close to 80% for PST and less than 10% for PSN.

Spectral Properties of Alpha-Cu2(OH/D)3Br at Room Temperature

2011 ◽  
Vol 391-392 ◽  
pp. 1493-1497
Author(s):  
Xiao Dong Liu ◽  
Dong Dong Meng ◽  
Xu Guang Zheng ◽  
Qi Xin Guo
Keyword(s):  
Comparative Analysis ◽  
Spectral Properties ◽  
Room Temperature ◽  
Single Phase ◽  
Group Analysis ◽  
Factor Group ◽  
Vibration Modes ◽  
Factor Group Analysis ◽  
Geometric Frustration ◽  
Copper Bromide

The newly identified magnetic geometric frustration material-botallackite-structure deuteroxyl copper bromide α-Cu2(OD)3Br sample was successfully synthesized in the same single phase (polycrystalline) as the H-isotope substituted sample of α-Cu2(OH)3Br, and its IR (4000-400 cm–1) absorption and Raman (4000-95 cm–1) spectra at room temperature are first, to the best of our knowledge, measured to study the corresponding relationship between these iso-structural compounds. Through the comparative analysis with those of α-Cu2(OH)3Br reported previously, we definitely assign or tentatively suggest their vibration modes according to the result of the factor group analysis.

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