Temperature-dependent isomorphous phase transition studies in molecular crystals of 2,4,4′-trimethoxybenzophenone

2010 ◽  
Vol 964 (1-3) ◽  
pp. 31-38 ◽  
Author(s):  
Hoong-Kun Fun ◽  
Ching Kheng Quah ◽  
Samuel Robinson Jebas ◽  
Lye-Hock Ong
Keyword(s):  
Phase Transition ◽  
Molecular Crystals ◽  
Temperature Dependent ◽  
Transition Studies

scholarly journals A Short Review of Current Computational Concepts for High-Pressure Phase Transition Studies in Molecular Crystals

Crystals ◽  
2020 ◽  
Vol 10 (2) ◽  
pp. 81 ◽  
Author(s):  
Denis A. Rychkov
Keyword(s):  
Phase Transition ◽  
High Pressure ◽  
Organic Compounds ◽  
Computational Study ◽  
Molecular Crystals ◽  
High Pressure Phase ◽  
Advantages And Disadvantages ◽  
High Pressure Phase Transition ◽  
Pressure Phase ◽  
Transition Studies

High-pressure chemistry of organic compounds is a hot topic of modern chemistry. In this work, basic computational concepts for high-pressure phase transition studies in molecular crystals are described, showing their advantages and disadvantages. The interconnection of experimental and computational methods is highlighted, showing the importance of energy calculations in this field. Based on our deep understanding of methods’ limitations, we suggested the most convenient scheme for the computational study of high-pressure crystal structure changes. Finally, challenges and possible ways for progress in high-pressure phase transitions research of organic compounds are briefly discussed.

Temperature-Dependent Solid-state Luminescence and Reversible Phase Transition of (n-Bu4N)[Au(SC6H3-3,5-Me2)2]

2003 ◽  
Vol 32 (11) ◽  
pp. 1002-1003 ◽  
Author(s):  
Seiji Watase ◽  
Takayuki Kitamura ◽  
Nobuko Kanehisa ◽  
Masami Nakamoto ◽  
Yasushi Kai ◽  
...  
Keyword(s):  
Phase Transition ◽  
Solid State ◽  
Temperature Dependent ◽  
Reversible Phase Transition ◽  
Reversible Phase ◽  
State Luminescence

scholarly journals Temperature Dependence of Electrical Properties and Crystal Structure of 0.29Pb(In1/2Nb1/2)O3–0.44Pb(Mg1/3Nb2/3)O3–0.27PbTiO3Single Crystals

2013 ◽  
Vol 2013 ◽  
pp. 1-5
Author(s):  
Qian Li ◽  
Yun Liu ◽  
Andrew Studer ◽  
Zhenrong Li ◽  
Ray Withers ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Phase Transition ◽  
Electrical Properties ◽  
Dielectric Permittivity ◽  
Neutron Diffraction ◽  
Electrical Measurement ◽  
Temperature Dependent ◽  
Electromechanical Properties ◽  
Polar Order

We characterized the temperature dependent (~25–200°C) electromechanical properties and crystal structure of Pb(In1/2Nb1/2)O3-Pb(Mg1/3Nb2/3)O3-PbTiO3single crystals usingin situelectrical measurement and neutron diffraction techniques. The results show that the poled crystal experiences an addition phase transition around 120°C whereas such a transition is absent in the unpoled crystal. It is also found that the polar order persists above the maximum dielectric permittivity temperature at which the crystal shows a well-defined antiferroelectric behavior. The changes in the electrical properties and underlying crystal structure are discussed in the paper.

The variational approach to the Glashow–Weinberg–Salam model

1987 ◽  
Vol 65 (4) ◽  
pp. 395-402 ◽  
Author(s):  
R. Manka ◽  
J. Sladkowski
Keyword(s):  
Phase Transition ◽  
Effective Potential ◽  
Variational Approach ◽  
Canonical Quantization ◽  
Temperature Dependent ◽  
Model Based

The variational approach to the Glashow–Weinberg–Salam model, based on canonical quantization, is presented. It is shown that taking into consideration the Becchi–Rouet–Stora symmetry leads to the correct, temperature-dependent, effective potential. This generalization of the Weinberg–Coleman potential leads to a phase transition of the first kind.

scholarly journals Ionic Conductivity and Phase Transition Behaviour in 4AgI-(1-)-2CuI System

2008 ◽  
Vol 2008 ◽  
pp. 1-4 ◽  
Author(s):  
Mohammed Hassan ◽  
Rfi Rafiuddin
Keyword(s):  
Phase Transition ◽  
Ionic Conductivity ◽  
Binary System ◽  
High Temperature Phase ◽  
Temperature Phase ◽  
Conductivity Measurements ◽  
Temperature Dependent ◽  
X Ray ◽  
Dsc Curves ◽  
Transition Behaviour

Samples of general formula 4AgI-(1-)-2CuI, , have been prepared and investigated by XRD, DSC, and temperature-dependent conductivity studies. X-ray diffractograms showed the presence of binary system consisting of AgI and in the sample . Cu-substituted samples showed very similar diffractograms to that of the pure compound which indicates that no effect for the substitution on the nature of the binary system. DSC curves showed the presence of phase transition whose temperature increased with ratio in the system. Ionic conductivity measurements confirmed the occurrence of the phase transition and showed that the high temperature phase is superionic conducting, whose conductivity increases with the increasing amount in the system.

scholarly journals Effect of Sintering Temperature on Metal-Insulator Phase Transition in La1-xCaxMnO3 Perovskites

2020 ◽  
Vol 2 (1) ◽  
pp. 37-42
Author(s):  
Arunachalam M ◽  
Thamilmaran P ◽  
Sakthipandi K
Keyword(s):  
Phase Transition ◽  
Bulk Modulus ◽  
Sintering Temperature ◽  
Magnetic Sensors ◽  
Temperature Dependent ◽  
Metal Insulator ◽  
Wide Range ◽  
Different Temperatures ◽  
Insulator Phase Transition

Lanthanum calcium based perovskites are found to be advantageous for the possible applications in magnetic sensors/reading heads, cathodes in solid oxide fuel cells, and frequency switching devices. In the present investigation La0.3Ca0.7MnO3 perovskites were synthesised through solid state reaction and sintered at four different temperatures such as 900, 1000, 1100 and 1200˚ C. X-ray powder diffraction pattern confirms that the prepared La0.3Ca0.7MnO3 perovskites have orthorhombic structure with Pnma space group. Ultrasonic in-situ measurements have been carried out on the La0.3Ca0.7MnO3 perovskites over wide range of temperature and elastic constants such as bulk modulus of the prepared La0.3Ca0.7MnO3 perovskites was obtained as function of temperature. The temperature-dependent bulk modulus has shown an interesting anomaly at the metal-insulator phase transition. The metal insulator transition temperature derived from temperature-dependent bulk modulus increases from temperature 352˚ C to 367˚ C with the increase of sintering temperature from 900 to 1200˚ C.

scholarly journals Experimental Observation of Temperature-Driven Topological Phase Transition in HgTe/CdHgTe Quantum Wells

2019 ◽  
Author(s):  
Maksim Zholudev ◽  
Aleksandr Kadykov ◽  
Mikhail Fadeev ◽  
Michal Marcinkiewicz ◽  
Sandra Ruffenach ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Phase Transition ◽  
Quantum Wells ◽  
Topological Insulator ◽  
Critical Magnetic Field ◽  
Topological Phase ◽  
Temperature Dependent ◽  
Transition Parameter ◽  
Topological Phase Transition ◽  
Band Insulator

We report on comparison between temperature-dependent magneto¬absorption and magnetotransport spectroscopy of HgTe/CdHgTe quantum wells in terms of detection of phase transition between topological insulator and band insulator states. Our results demonstrate that temperature-dependent magnetospectroscopy is a powerful tool to discriminate trivial and topological insulator phases, yet magnetotransport method is shown to have advantages for clear manifestation of the phase transition with accurate quantitative values of transition parameter (i.e. critical magnetic field Bc).

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