Phase transitions of (1:1) alkaline salts of TCNQ as studied by vibronic intensity enhancement in the infrared spectra

1999 ◽  
Vol 67 (9) ◽  
pp. 3864 ◽  
Author(s):  
Renato Bozio
Keyword(s):  
Phase Transitions ◽  
Infrared Spectra ◽  
Intensity Enhancement

scholarly journals Investigation of phase transitions in liquid crystal 12BBAA using window clustering of infrared spectra

2021 ◽  
Vol 341 ◽  
pp. 117233
Author(s):  
Natalia Osiecka-Drewniak ◽  
Mirosław A. Czarnecki ◽  
Zbigniew Galewski
Keyword(s):  
Phase Transitions ◽  
Liquid Crystal ◽  
Infrared Spectra

Infrared Spectra of the CH3NH3PbI3 Hybrid Perovskite: Signatures of Phase Transitions and of Organic Cation Dynamics

2020 ◽  
Vol 124 (42) ◽  
pp. 23307-23316
Author(s):  
Kirill N. Boldyrev ◽  
Vasilisa E. Anikeeva ◽  
Olga I. Semenova ◽  
Marina N. Popova
Keyword(s):  
Phase Transitions ◽  
Infrared Spectra ◽  
Organic Cation ◽  
Hybrid Perovskite

Vibronic intensity enhancement in the infrared spectra of heavily doped (CH)x and (CD)x

1979 ◽  
Vol 71 (11) ◽  
pp. 4614-4619 ◽  
Author(s):  
J. F. Rabolt ◽  
T. C. Clarke ◽  
G. B. Street
Keyword(s):  
Infrared Spectra ◽  
Intensity Enhancement ◽  
Heavily Doped

RAMAN AND INFRARED STUDY OF PHASE TRANSFORMATION IN CRYSTALLINE HYDROGEN IODIDE AND DEUTERIUM IODIDE HI AND DI

1989 ◽  
Vol 03 (11) ◽  
pp. 1671-1679 ◽  
Author(s):  
W.S. TSE ◽  
C.S. FANG ◽  
A. ANDERSON ◽  
B.H. TORRIE
Keyword(s):  
Phase Transformation ◽  
Phase Transitions ◽  
Melting Point ◽  
Infrared Spectra ◽  
Hydrogen Iodide ◽  
Temperature Dependent ◽  
Two Phase ◽  
Infrared Study ◽  
X Ray ◽  
Temperature Range

Raman and infrared spectra of polycrystalline HI and DI in the region of lattice and internal modes for all three phases have been recorded over the temperature range 18 K to the melting point. The temperature dependent Raman and infrared results are consistent with the X-ray and neutron work that two phase transitions occur at HI and DI involving reorientation of the HI and DI molecules as a whole.

The Effect of Substituents at Benzoic Ring on the Parameters of Cholesteryl Benzoates Infrared Spectra in Phase Transitions

1983 ◽  
Vol 98 (1) ◽  
pp. 175-182 ◽  
Author(s):  
A. D. Laskovetz ◽  
I. I. Gorina ◽  
L. S. Gorbatenko ◽  
I. G. Chistyakov ◽  
G. V. Mikhailenko
Keyword(s):  
Phase Transitions ◽  
Infrared Spectra ◽  
Effect Of Substituents

Effects of pressure on the infrared spectra of some heterocyclic organosilicon and organogermanium compounds

1984 ◽  
Vol 37 (1) ◽  
pp. 23 ◽  
Author(s):  
SD Hamann ◽  
P Mazerolles ◽  
A Faucher ◽  
G Manuel
Keyword(s):  
Phase Transitions ◽  
Conformational Changes ◽  
Infrared Spectra ◽  
Functional Group ◽  
Organogermanium Compounds ◽  
Transannular Interaction

Measurements have been made of the infrared spectra of eight solid heterocyclic organosilicon and organogermanium compounds at pressures up to 5 GPa at normal temperature. Evidence is found of reversible conformational changes under pressure, and of phase transitions in some of the compounds. Unexpectedly, it appears that compression does not favour the transannular interaction that exists, in some cases, between the heteroatom (silicon or germanium) and a functional group on the opposite side of the ring.

INFRARED SPECTRA AND CRYSTALLINE PHASE TRANSITIONS OF AMMONIUM NITRATE

1964 ◽  
Vol 42 (1) ◽  
pp. 57-62 ◽  
Author(s):  
A. Théorêt ◽  
C. Sandorfy
Keyword(s):  
Phase Transitions ◽  
Melting Point ◽  
Phase I ◽  
Ammonium Nitrate ◽  
Air Temperature ◽  
Infrared Spectra ◽  
Crystalline Phase ◽  
Rapid Cooling ◽  
Symmetry Properties ◽  
Crystalline Films

The infrared spectra of solid crystalline films of ammonium nitrate were measured at temperatures ranging between the melting point (169 °C) and liquid air temperature (−190 °C). Four different spectra were obtained which are shown to belong to phase I, II, IV, and (very probably) VII. Phases III and V were not encountered; only transitions [Formula: see text], [Formula: see text], and [Formula: see text] were observed. A spectrum measured at −190 °C after rapid cooling is shown to correspond to a mixture of phases IV and VII. The symmetry properties of the different phases are discussed in relation with their infrared spectra.

THE INFRARED SPECTRA AND PHASE TRANSITIONS OF SOLID PIPERIDINIUM HALIDES

1962 ◽  
Vol 40 (4) ◽  
pp. 615-621 ◽  
Author(s):  
A. Cabana ◽  
C. Sandorfy
Keyword(s):  
Phase Transition ◽  
Phase Transitions ◽  
Infrared Spectra ◽  
Low Temperatures ◽  
Room Temperature ◽  
Solid Films

The infrared spectra of solid films of piperidinium halides were measured at both room temperature and low temperatures. The spectra of the chloride and the bromide are not appreciably affected by cooling, but the spectrum of the iodide exhibits spectacular changes. These changes are explained by assuming the occurrence of a phase transition at about −15 °C. The possibility of a "chair" → "boat" interconversion is also discussed.

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