Structural Phase Transitions in Solid tert-Butylammonium Nitrate as Studied by Differential Thermal Analysis and 1H-NMR

1989 ◽  
Vol 44 (1) ◽  
pp. 71-74
Author(s):  
Hiroyuki Ishida ◽  
Tadashi Iwachido ◽  
Naomi Hayama ◽  
Ryuichi Ikeda ◽  
Miyuki Hashimoto ◽  
...  
Keyword(s):  
Thermal Analysis ◽  
Differential Thermal Analysis ◽  
Solid Phase ◽  
Structural Phase ◽  
Structural Phase Transitions ◽  
Self Diffusion ◽  
H Nmr ◽  
Nmr Techniques ◽  
Plastic Phase ◽  
Solid Phases

Abstract Seven solid phases including three metastable phases of (CH3)3CNH3NO3 were revealed by differential thermal analysis in the temperature range between 80 K and the melting point (418 K), and cationic dynamics in each phase was studied by use of 1H-NMR techniques. The highesttemperature solid phase obtainable above 412 K was found to be an ionic plastic phase, where the cations perform rapid translational self-diffusion and overall rotation about their center of gravity.

1H NMR and Thermal Studies of CH3NH3Br in a Metastable Solid Phase Newly Found above 483 K

1989 ◽  
Vol 44 (8) ◽  
pp. 738-740 ◽  
Author(s):  
Masataka Tansho ◽  
Daiyu Nakamura ◽  
Ryuichi Ikeda
Keyword(s):  
Thermal Analysis ◽  
Differential Thermal Analysis ◽  
Solid Phase ◽  
Thermal Studies ◽  
Stable Phase ◽  
Self Diffusion ◽  
H Nmr ◽  
Plastic Phase ◽  
Metastable Solid Phase ◽  
Absorption Measurements

Abstract By differential thermal analysis a new high-temperature solid phase of methylammonium bromide was found between 483 K and its “melting point” (510 K). 1H NMR absorption measurements revealed the presence of rapid 3D translational self-diffusion and overall rotation of methylammonium cations in this phase. These cationic motions are quite analogous to those of methylammonium iodide in its ionic plastic phase. Surprisingly, this plastic-like phase is metastable, the stable phase in the same temperature range being liquid.

Solid phase precipitates in (Zr,Th)-OH-(oxalate, malonate) ternary aqueous system

2009 ◽  
Vol 97 (4-5) ◽  
Author(s):  
Taishi Kobayashi ◽  
Takayuki Sasaki ◽  
I. Takagi ◽  
Hirotake Moriyama
Keyword(s):  
Thermal Analysis ◽  
Differential Thermal Analysis ◽  
Solid Phase ◽  
Aqueous System ◽  
Carboxylate Ligand ◽  
X Ray Diffraction ◽  
Large Excess ◽  
X Ray ◽  
Acidic Conditions ◽  
Solid Phases

AbstractThe solubility-limiting solid phases in the ternary aqueous systems of Zr(IV)/OH/oxalate, Zr(IV)/OH/malonate, Th(IV)/OH/oxalate and Th(IV)/OH/malonate were characterized by elemental analysis, X-ray diffraction, thermogravimetric analysis and differential thermal analysis. The ternary solid phase of M(IV)/OH/carboxylate was observed to form, even under acidic conditions, depending on the pH and the concentration of carboxylate ligand. In the presence of a large excess of carboxylic acid, however; the binary M(IV)-carboxylate solid phase formed.

Structural Phase Transitions and Cationic Motions in Pvridinium Dichloroiodate(I) as Studied by 1H NMR, Differential Thermal Analysis, and Powder X-Ray Diffraction

1989 ◽  
Vol 44 (11) ◽  
pp. 1111-1115 ◽  
Author(s):  
Reiko Watanabe ◽  
Tetsuo Asaji ◽  
Yoshihiro Furukawa ◽  
Daiyu Nakamura ◽  
Ryuichi Ikeda
Keyword(s):  
Thermal Analysis ◽  
Differential Thermal Analysis ◽  
Phase Transitions ◽  
Room Temperature ◽  
Structural Phase ◽  
Spin Lattice Relaxation ◽  
Growth Time ◽  
Stable Phase ◽  
Temperature Phase ◽  
H Nmr

For crystals of pyridinium dichloroiodate (I), (pyH)ICl2, the temperature dependences of the 1H NMR spin-lattice relaxation time T1 and the 1H second moment M2 were determined. M2 was found to be small (~ 1 G2) above room temperature, indicating that the cations perform rapid reorientational motion about their pseudohexad axis perpendicular to the cationic plane. 1H T1 at its minimum was unusually long, indicating this motion occurring in the low symmetry local environments. Phase transitions between stable solid phases were revealed at 282 and 373 K by the 1H NMR measurements and differential thermal analysis. The highest-temperature phase was easily supercooled and transformed reversibly into another metastable phase and back on cooling and warming at almost the same temperature of 138 K. The kinetics of the phase transition from the supercooled to the stable phase at room temperature was analyzed using an Avrami type relation. The growth time of the stable phase was estimated to be about 14 h at room temperature

Differential Thermal Analysis and PVT Measurements on 2,2,2-Trichloro-ethanol Under High Pressure

1997 ◽  
Vol 52 (6-7) ◽  
pp. 493-501 ◽  
Author(s):  
M. Jenau ◽  
M. Sandmann ◽  
A. Würflinger ◽  
J. Ll. Tamarit
Keyword(s):  
Thermal Analysis ◽  
Differential Thermal Analysis ◽  
Atmospheric Pressure ◽  
Solid Phase ◽  
Melting Curve ◽  
Phase Behaviour ◽  
Enthalpy Changes ◽  
Pvt Measurements ◽  
Plastic Phase ◽  
Lower Temperature

Abstract The phase behaviour, the calorimetric and volumetric properties of 2,2,2-trichloro-ethanol (TCE) have been studied with differential thermal analysis (DTA) and pVT measurements in the pressure range 1 atm to 300 MPa and temperatures between 250 K to 355 K. TCE displays a metastable plastic phase (solid I') and a non-plastic solid phase II at atmospheric pressure. At least two pressure-induced solid phases have been detected: a stable plastic phase (solid I') and a non-plastic phase (solid III). There are two sets of triple points: a) 123 MPa and 308 K with the phases solid I, solid II and the liquid, b) 243 MPa and 316 K for solid I, II, III. Furthermore a metastable low-temperature brittle form (solid II') has been found, which transforms to solid I at a considerably lower temperature than solid II. The melting curve of solid I' can be pursued to higher pressures up to 260 MPa. On the other hand, the melting curve of the stable plastic phase solid I can be extrapolated beyond the triple point to pressures below 123 MPa. Volume and enthalpy changes are reported for all phase transitions.

Ionic Dynamics in the Ionic Plastic Crystal NH4NO2

2007 ◽  
Vol 62 (10-11) ◽  
pp. 633-638 ◽  
Author(s):  
Hisashi Honda
Keyword(s):  
High Temperature ◽  
Nmr Spectra ◽  
Solid Phase ◽  
High Temperature Phase ◽  
Temperature Phase ◽  
Plastic Crystal ◽  
Self Diffusion ◽  
H Nmr ◽  
Isotropic Reorientation ◽  
Plastic Phase

Using 1H NMR T1 and T1ρ measurements self-diffusion of NH4 + with an activation energy of (80 ± 10) kJ mol−1 was detected in the highest-temperature phase of NH4NO2 crystals. Narrow 15N NMR spectra of 15NH4NO2 and NH415NO2 revealed that the isotropic reorientation rates of NH4 + and NO2 − ions are rapid in the high-temperature solid phase. These results suggest that the high-temperature phase of NH4NO2 crystals forms an ionic plastic phase.

Differential Thermal Analysis and Dielectric Studies on Neopentanol under Pressure

1992 ◽  
Vol 47 (11) ◽  
pp. 1127-1134 ◽  
Author(s):  
H. G. Kreul ◽  
R. Waldinger ◽  
A. Würflinger
Keyword(s):  
Thermal Analysis ◽  
Differential Thermal Analysis ◽  
Relaxation Time ◽  
Phase Transitions ◽  
Dielectric Relaxation ◽  
Pressure Dependence ◽  
Dielectric Relaxation Time ◽  
Dielectric Studies ◽  
Dielectric Measurements ◽  
Plastic Phase

Abstract Differential thermal analysis (DTA) and dielectric measurements have been performed on 2,2-dimethyl- 1-propanol (neopentanol) up to 200 MPa. Neopentanol exhibits at least one orientationally disordered (ODIC) phase (solid I) that transforms at lower temperatures to a non-plastic phase (solid II). There is evidence of a further ODIC phase denoted as solid I'. The pressure dependence of the phase transitions and the dielectric behaviour up to frequencies of 13 MHz are described. Activation enthalpies and volumes are derived from the dielectric relaxation time and compared with results for other alcohols

Behavior of thermal properties of AgCu1−xFexS compounds under non-isothermal conditions

2019 ◽  
Vol 33 (28) ◽  
pp. 1950339 ◽  
Author(s):  
Y. I. Aliyev ◽  
P. R. Khalilzade ◽  
Y. G. Asadov ◽  
T. M. Ilyasli ◽  
F. M. Mammadov ◽  
...  
Keyword(s):  
Phase Transition ◽  
Thermal Analysis ◽  
Differential Thermal Analysis ◽  
Thermal Properties ◽  
Phase Transitions ◽  
Structural Phase Transition ◽  
Structural Phase ◽  
Partial Replacement ◽  
Isothermal Conditions ◽  
The Given

AgCu[Formula: see text]Fe[Formula: see text]S compounds were synthesized by partial Cu[Formula: see text][Formula: see text][Formula: see text]Fe replacement in the AgCuS crystal at a concentration range of 0[Formula: see text][Formula: see text][Formula: see text]x[Formula: see text][Formula: see text][Formula: see text]0.03. In the differential thermal analysis spectrum obtained at a temperature range of 300 K[Formula: see text][Formula: see text][Formula: see text]T[Formula: see text][Formula: see text][Formula: see text]1300 K, endoeffect corresponding to the structural phase transition in the AgCuS compound was observed at the temperature T[Formula: see text]=[Formula: see text]938 K. It has been determined that this result is also observed in the AgCu[Formula: see text]Fe[Formula: see text]S compound obtained by partial replacement of Cu atoms by Fe atoms. However, in the compound of AgCu[Formula: see text]Fe[Formula: see text]S this effect was observed at higher temperatures. The thermal capacities and enthalpies of phase transitions were calculated for the given compounds.

Differential Thermal Analysis and Dielectric Studies on 2-Methyl-2-Nitro-Propane under High Pressure

1995 ◽  
Vol 50 (4-5) ◽  
pp. 502-504 ◽  
Author(s):  
D. Büsing ◽  
M. Jenau ◽  
J. Reuter ◽  
A. Würflinger ◽  
J. Li. Tamarit
Keyword(s):  
Thermal Analysis ◽  
Differential Thermal Analysis ◽  
Temperature Phase ◽  
Dielectric Studies ◽  
Static Permittivity ◽  
Coexistence Region ◽  
Disordered Phase ◽  
Plastic Phase ◽  
Related Compounds ◽  
Low Temperature Phase

Abstract Differential thermal analysis and dielectric studies under pressures up to 300 MPa and temperatures of about 200 to 350 K have been performed on 2-methyl-2-nitro-propane (TBN). TBN displays an orientationally disordered phase (ODIC), solid I, and two non-plastic phases, solids II and III. The coexistence region of the plastic phase I increases with increasing pressure, whereas the low-temperature phase II apparently vanishes at a triple point I, II, III, above 300 MPa. The static permittivity increases on freezing, characterizing the solid I as an ODIC phase. In the frame of the Kirkwood-Onsager-Fröhlich theory the g-factor is about unity, discounting specific dielectric correlations. The dielectric behaviour of TBN is similar to previously studied related compounds, such as 2-chloro-2-methyl-propane or 2-brome- 2-methyl-propane

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