Phase Transitions and Ionic Motions in Solid Trimethylethylammonium Iodide Studied by 1H and 127I NMR, Electrical Conductivity, X-ray Diffraction, and Thermal Analysis

1996 ◽  
Vol 100 (4) ◽  
pp. 433-439 ◽  
Author(s):  
Hiroyuki Ishida ◽  
Yoshihiro Furukawa ◽  
Setsuo Kashino ◽  
Setsuko Sato ◽  
Ryuichi Ikeda
Keyword(s):  
Thermal Analysis ◽  
Electrical Conductivity ◽  
Phase Transitions ◽  
X Ray Diffraction ◽  
X Ray

scholarly journals S tudies on the phase transitions and properties of tungsten (VI) oxide nanoparticles by X - Ray diffraction (XRD) and thermal analysis

2017 ◽  
Vol 26 (1) ◽  
Author(s):  
S.F. Abdullah ◽  
S. Radiman ◽  
M.A. Abdul Hamid ◽  
N.B. Ibrahim
Keyword(s):  
Thermal Analysis ◽  
Phase Transitions ◽  
Photoelectron Spectroscopy ◽  
Average Diameter ◽  
Amorphous Structure ◽  
X Ray Diffraction ◽  
X Ray ◽  
Calcination Temperatures ◽  
Transmission Electron ◽  
Scherrer Formula

Tungsten (VI) oxide, WO3nanoparticles were synthesized by colloidal gas aphrons(CGAs) technique.The resultant WO3nanoparticleswere characterized by thermogravimetric-differential thermal analysis (TG-DTA) and X-Ray diffraction (XRD) measurements in order to determine the phase transitions, the crystallinity and the size of theWO3nanoparticles. As a comparison, transmission electron microscope (TEM) was used to investigate the size of the WO3nanoparticles. The result from XRD and DTA show that the formation of polymorphsWO3nanoparticles have the following sequence: orthorhombic (b-WO3)®monoclinic (g-WO3) ®triclinic (d-WO3) ®monoclinic (e-WO3) with respect to the calcination temperature of 400, 500, 600 and 700°C. No diffraction peaks were found in the X-Ray diffraction measurements for the sample heat treated at 300°C (as-prepared), suggesting that an amorphous structure was obtained at this temperature whereas the crystallinity had been obtained by the other samples of theWO3nanoparticles at the calcination temperatures of 400, 500, 600 and 700°C. It is also found that the X-Ray diffraction measurements produced an average diameter of (30 ±5), (50 ±5), (150 ±10) and (200 ±10) nm at calcination temperatures of 400, 500, 600 and 700°C respectively by using Debye-Scherrer formula. The TG curve revealed that the WO3nanoparticles is purely anhydrous since the weight loss is insignificant (0.3 –1.4) % from 30 until 600°C for the WO3nanoparticles calcined at 400°C. Finally, the composition and the purity of the WO3nanoparticleshave been examined by X-Ray photoelectron spectroscopy (XPS). Theresults indicate no significant changes to the composition and the purity of the WO3nanoparticle produced due to the temperature variations 

Thermal analysis of the phases of HMX using X-ray diffraction

1993 ◽  
Vol 204 (1) ◽  
Author(s):  
M. Herrmann ◽  
W. Engel ◽  
N. Eisenreich
Keyword(s):  
Thermal Analysis ◽  
Thermal Expansion ◽  
Phase Transitions ◽  
Diffraction Pattern ◽  
X Ray Diffraction ◽  
Volume Changes ◽  
X Ray ◽  
Temperature Range

AbstractThe 4 phases of HMX and its transitions were investigated using X-ray diffraction. The phases were heated stepwise in a temperature range from 170 K to 510 K, measuring a diffraction pattern after each step.The thermal expansion of the different phases and the volume changes during the phase transitions were obtained. Anomalies and strongly anisotropic expansions were observed withThe highest thermal expansion was found with

Structures and phase transitions of (BrCH2CH2NH3)2CdBr4 and (BrCH2CH2CH2NH3)2CdBr4 as investigated by 81Br NQR, DTA, and single-crystal X-ray diffraction

2020 ◽  
Vol 75 (3) ◽  
pp. 295-302
Author(s):  
Hideta Ishihara ◽  
Asuka Koga ◽  
Koh-ichi Suzuki ◽  
Hiromitsu Terao
Keyword(s):  
Thermal Analysis ◽  
Hydrogen Bonding ◽  
Differential Thermal Analysis ◽  
Phase Transitions ◽  
Hydrogen Bonds ◽  
Layered Perovskite ◽  
X Ray Diffraction ◽  
X Ray ◽  
81Br Nqr ◽  
Successive Phase

AbstractThe crystal structures of (BrCH2CH2NH3)2CdBr4 (1) and (BrCH2CH2CH2NH3)2CdBr4 (2) have been determined at T = 113 K: orthorhombic, Pbcn, a = 843.8(4), b = 775.4(4), c = 2339.6(11) pm, Z = 4 for 1; orthorhombic, Pbcn, a = 858.7(3), b = 783.6(2), c = 2519.4(7) pm, Z = 4 for 2. Both crystals are isomorphic, showing distinctive layered perovskite-related structures, in which the cations orient their aliphatic parts toward each other in their cation layers and connect to the infinite anion layers with their ammonium parts through N–H · · · Br hydrogen bonds. 81Br NQR and differential thermal analysis measurements for both compounds revealed the existence of successive phase transitions as seen in n-(CH3CH2CH2NH3)2CdBr4 (3). These phase transitions appear to be induced by the activated motions of the cations. The changes in the hydrogen bonding schemes resulting from the motions of the cations lead to the different phases of the respective crystals.

scholarly journals Studies on the phase transitions and properties of tungsten (VI) oxide nanoparticles by X-Ray diffraction (XRD) and thermal analysis

2017 ◽  
Vol 26 (1) ◽  
pp. 13-20 ◽  
Author(s):  
S.F. Abdullah ◽  
S. Radiman ◽  
M.A. Abdul Hamid ◽  
N.B, Ibrahim
Keyword(s):  
Thermal Analysis ◽  
Phase Transitions ◽  
Photoelectron Spectroscopy ◽  
Average Diameter ◽  
Amorphous Structure ◽  
X Ray Diffraction ◽  
X Ray ◽  
Calcination Temperatures ◽  
Transmission Electron ◽  
Scherrer Formula

Tungsten (VI) oxide, WO3 nanoparticles were synthesized by colloidal gas aphrons (CGAs) technique.  The resultant WO3 nanoparticles were characterized by thermogravimetric-differential thermal analysis (TG-DTA) and X-Ray diffraction (XRD) measurements in order to determine the phase transitions, the crystallinity and the size of the WO3 nanoparticles. As a comparison, transmission electron microscope (TEM) was used to investigate the size of the WO3 nanoparticles.  The result from XRD and DTA show that the formation of  polymorphs WO3 nanoparticles have the following sequence: orthorhombic (bWO3) ® monoclinic (g-WO3) ® triclinic (d-WO3) ® monoclinic (e-WO3) with respect to the calcination temperature of 400, 500, 600 and 700°C.  No diffraction  peaks were found in the X-Ray diffraction measurements for the sample heat treated at 300°C (as-prepared), suggesting that an amorphous structure was  obtained at this temperature whereas the crystallinity had been obtained by the other samples of the WO3 nanoparticles at the calcination temperatures of 400, 500, 600 and 700°C.  It is also found that the X-Ray diffraction measurements produced an average diameter of (30 ± 5), (50 ± 5), (150 ± 10) and (200 ± 10) nm at calcination temperatures of 400, 500, 600 and 700°C respectively by using  Debye-Scherrer formula.  The TG curve revealed that the WO3 nanoparticles is purely anhydrous since the weight loss is insignificant (0.3 – 1.4) % from 30 until  600°C for the WO3 nanoparticles calcined at 400°C.  Finally, the composition and the purity of the WO3 nanoparticles have been examined by X-Ray photoelectron spectroscopy (XPS).  The results indicate no significant changes to the composition and the purity of the WO3 nanoparticles produced due to the  temperature variations.                                             

Effect of Homogenizing Treatment on Microstructure and Property of Al-Zn-Mg-Cu-Zr Aluminum Alloy

2016 ◽  
Vol 877 ◽  
pp. 587-592
Author(s):  
Gao Song Wang ◽  
Qing Qiang Chen ◽  
Kai Tao ◽  
Qi Chao Chen ◽  
Zhi Hao Zhao
Keyword(s):  
Heat Treatment ◽  
Thermal Analysis ◽  
Electrical Conductivity ◽  
Homogenization Temperature ◽  
Ingot Metallurgy ◽  
X Ray Diffraction ◽  
Slow Cooling ◽  
X Ray ◽  
Processing Effects ◽  
Equilibrium Phases

A series of Al-6.3Zn-2.3Mg-2.3Cu-0.15Zr alloys with different reduce of Zn, Mg, Cu and Zr were prepared by ingot-metallurgy processing. Effects of homogenization on the microstructure and properties of Al-Zn-Mg-Cu-Zr aluminium alloy were respectively studied by means of metallographic microscopy, electrical conductivity test, differential thermal analysis and X-ray diffraction phase analysis. The results indicated that the overheating temperature of these alloys is between 473°C and 477°C, and there was little difference to the overheating temperature of 7050 alloy. During homogenization process, using three kinds of developed heat treatment of homogenization of 7050 alloy, with the rising of homogenization temperature and the complication of the homogenization heat treatment, the electrical conductivity decreased and hardness gradually increased. The three-step homogenization has a better effect than single homogenization, as it can completely eliminate the endothermic peak of non-equilibrium phases. Many MgZn2 phases are present in the ingot with three-step homogenization and slow cooling.

Effect of CdI2 on electrical conductivity and phase transition behavior in AgI

1981 ◽  
Vol 59 (18) ◽  
pp. 2685-2688 ◽  
Author(s):  
Mahadeva Natarajan ◽  
Etalo A. Secco
Keyword(s):  
Phase Transition ◽  
Thermal Analysis ◽  
Electrical Conductivity ◽  
Differential Thermal Analysis ◽  
Phase Transitions ◽  
Phase Transition Behavior ◽  
Polymorphic Behavior ◽  
X Ray ◽  
Transition Behavior ◽  
Low Concentrations

The phase transitions occurring in AgI containing dissolved CdI2 have been examined by differential thermal analysis (DTA), electrical conductivity technique, and X-ray diffractometry. The electrical conductivity and polymorphic behavior of AgI is significantly modified by low concentrations of CdI2. The results are interpreted in terms of substitutional Cd2+ and Ag+ vacancies in AgI sublattice.

Phase Transitions in Perovskite Phases of Strontium Silicoantimonates

2016 ◽  
Vol 845 ◽  
pp. 34-37 ◽  
Author(s):  
Yulia N. Kuryleva ◽  
Olga A. Chalaya ◽  
D.A. Zakharyevich
Keyword(s):  
Thermal Analysis ◽  
Phase Transitions ◽  
Room Temperature ◽  
Water Molecules ◽  
Chemical Transformations ◽  
X Ray Diffraction ◽  
Oxygen Sublattice ◽  
Structural Water ◽  
X Ray ◽  
The Third

The paper presents the results of the study of phase transitions in the system Sr-Sb-Si-O by means of X-ray diffraction, thermal analysis, dielectric spectroscopy. Four effects are observed in the interval from room temperature to 800°C. The first and last are chemical transformations due to dehydration and loss of oxygen, respectively. The second is a transition from tetragonal to cubic perovskite structure, and the third is disordering transition in oxygen sublattice possibly due to the desorption of structural water molecules

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