Phase transitions in vibrational spectra of crystals of the triglycine sulfate family

1996 ◽  
Vol 63 (6) ◽  
pp. 865-871 ◽  
Author(s):  
A. M. Malyarevich ◽  
M. R. Posledovich
Keyword(s):  
Phase Transitions ◽  
Vibrational Spectra ◽  
Triglycine Sulfate

Study of the phase transitions of (DI-DCNQI)2X using vibronic and vibrational spectra

2001 ◽  
Vol 120 (1-3) ◽  
pp. 1091-1092 ◽  
Author(s):  
M. Meneghetti ◽  
C. Pecile ◽  
K. Kanoda ◽  
K. Hiraki ◽  
K. Yakushi
Keyword(s):  
Phase Transitions ◽  
Vibrational Spectra

Phonon spectra of ortho -dinitrotetramethylbenzene crystals

1987 ◽  
Vol 65 (9) ◽  
pp. 2122-2125 ◽  
Author(s):  
Paolo Sgarabotto ◽  
Mario Braghetti ◽  
Rosario Sergio Cataliotti ◽  
Giulio Paliani ◽  
Salvatore Sorriso ◽  
...  
Keyword(s):  
Group Theory ◽  
Phase Transitions ◽  
Solid State ◽  
Melting Point ◽  
Nitro Group ◽  
Vibrational Spectra ◽  
Lattice Dynamics ◽  
Solid Phase ◽  
Methyl Group ◽  
Phonon Spectra

We have studied the vibrational spectra and thermal behaviour of ortho-dinitrotetramethylbenzene (o-DNTMB) to learn more about its molecular and lattice dynamics. The molecule undergoes two solid–solid phase transitions, close to the melting point, which could be explained by the relaxation of forces hindering the methyl-group and nitro-group free rotations. We have deduced the nature of the solid state vibrational motions, particularly those of lattice phonons, using group theory.

Two Pressure Induced Phase Transitions in Triglycine Sulfate

1959 ◽  
Vol 31 (3) ◽  
pp. 856-856 ◽  
Author(s):  
H. L. Suchan ◽  
H. G. Drickamer
Keyword(s):  
Phase Transitions ◽  
Triglycine Sulfate

RbAsF6, CsAsF6 und RbSbF6: Kristallstrukturen, Thermische Phasenumwandlungen und Schwingungsspektren / RbAsF6, CsAsF6 and RbSbF6: Crystal Structures, Thermal Phase Transitions, and Vibrational Spectra

1998 ◽  
Vol 53 (1) ◽  
pp. 75-80 ◽  
Author(s):  
Caroline Röhr ◽  
Sandra Loss
Keyword(s):  
Phase Transitions ◽  
Vibrational Spectra ◽  
Structure Type ◽  
Lattice Constants ◽  
Cscl Type ◽  
Thermal Phase ◽  
Thermal Phase Transitions ◽  
Fluorine Ions ◽  
Alkaline Cations ◽  
Complex Anions

The title compounds are isostructural to CsSbF6 and crystallize with the KOsF6 structure type (space group RS, Z = 3) with the lattice constants a = 749.7(1) pm, c = 758.9(1) pm (RbAsF6), a = 772.3(1) pm, c = 805.0(1) pm (CsAsF6) and a = 767.0(1) pm, c = 786.1(2) pm (RbSbF6). The structures exibit nearly ideal [MF6]– octahedra, the alkaline cations are coordinated by 12 fluorine ions in a distorted cuboctahedral geometry. Cations and complex anions form a slightly distorted CsCl arrangement. On heating, the arsenates transform to a NaCl arrangement with disordered [AsF6] ions, whereas the antimonates of Rb and Cs form the corresponding disordered CsCl type at higher temperatures. The phase transitions and the i. r. and Raman spectra as well as the structural relations to the remaining hexafluoropnictates AI[MVF6] are discussed.

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