A first principles lattice dynamics and Raman spectra of the ferroelastic rutile to CaCl2 phase transition in SnO2 at high pressure

2013 ◽  
Vol 44 (6) ◽  
pp. 926-933 ◽  
Author(s):  
Sanjay D. Gupta ◽  
Sanjeev K. Gupta ◽  
Prafulla K. Jha ◽  
N. N. Ovsyuk
Keyword(s):  
Phase Transition ◽  
High Pressure ◽  
Raman Spectra ◽  
First Principles ◽  
Lattice Dynamics

High-pressure structural phase transition and metallization in Ga2S3 under non-hydrostatic and hydrostatic conditions up to 36.4 GPa

2021 ◽  
Author(s):  
Linfei Yang ◽  
Jianjun Jiang ◽  
Lidong Dai ◽  
Haiying Hu ◽  
Meiling Hong ◽  
...  
Keyword(s):  
Phase Transition ◽  
Raman Spectroscopy ◽  
High Pressure ◽  
Structural Properties ◽  
Structural Phase Transition ◽  
First Principles ◽  
Theoretical Calculations ◽  
Structural Phase

The vibrational, electrical and structural properties of Ga2S3 were explored by Raman spectroscopy, EC measurements, HRTEM and First-principles theoretical calculations under different pressure environments up to 36.4 GPa.

scholarly journals Novel structural phases and the properties of LaX (X = P, As) under high pressure: first-principles study

RSC Advances ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 3058-3070
Author(s):  
Yu Zhou ◽  
Lan-Ting Shi ◽  
A-Kun Liang ◽  
Zhao-Yi Zeng ◽  
Xiang-Rong Chen ◽  
...  
Keyword(s):  
Phase Transition ◽  
High Pressure ◽  
Thermodynamic Properties ◽  
First Principles ◽  
Electronic Structures ◽  
Pressure Range ◽  
Mechanical Stability ◽  
First Principles Study

The structures, phase transition, mechanical stability, electronic structures, and thermodynamic properties of lanthanide phosphates (LaP and LaAs) are studied in the pressure range of 0 to 100 GPa by first principles.

scholarly journals Phase Transition and Polymerization of Acetonitrile under High Pressure

2014 ◽  
Vol 70 (a1) ◽  
pp. C763-C763
Author(s):  
Haiyan Zheng ◽  
Kuo Li ◽  
George Cody ◽  
Chris Tulk ◽  
Jamie Molaison ◽  
...  
Keyword(s):  
Phase Transition ◽  
High Pressure ◽  
Reaction Mechanism ◽  
Neutron Diffraction ◽  
Raman Spectra ◽  
Hydrogen Transfer ◽  
Layer Structure ◽  
Van Der Waals ◽  
Orthorhombic Phase ◽  
Organic Polymer

Successful application of high pressure on synthesis of organic polymer, including the conducting polymer and super hard materials depends on the knowledge of reaction mechanism. The evolution of crystal structure under high pressure especially the structure close to transition pressure is crucial to conclude the reaction mechanism. Nitriles represent a large class of interstellar molecules and are the potential source of amino acids. Understanding its behavior at extreme conditions has gained increasing attention recently. Acetonitrile (CH3CN), the simplest organic compound with C≡N triple bond, can act as a model system for studying the pressure induced polymerization. The phase transition of acetonitrile under high pressure has been studied extensively.[1-3] However, it is still controversial and there is no any detailed discussion about its polymerization mechanism under high pressure. Here, we report the in-situ high pressure Raman spectra and powder neutron diffraction results on CD3CN, which indicates a minor phase transition at 5 GPa. The neutron diffraction shows that CD3CN keeps the orthorhombic phase from 1.66 GPa to 20.58 GPa which is very close to the reaction pressure. The week hydrogen bonding CD...N arranges the molecule into 3-dimensional framework which can be treated as two sets of diamond like structures interpenetrating with each other. Interestingly, the observed N...D distance is 1.984 Å at 20.58 GPa, shorter than the van der Waals distance of N...H (2.75 Å) by 28%. The van der Waals separation is often taken as a reference distance for the molecular instability. Thus, a hydrogen transfer process during the polymerization can be concluded. This deduction is also supported by the solid state NMR and FTIR results of the recovered polymerized CH3CN (p-CH3CN) from high pressure. In addition, the atomic pair distribution function and Raman spectra indicate the p-CD3CN or p-CH3CN has a random packed layer structure with nano-graphene lattice.

scholarly journals High-pressure formation of antimony nitrides: a first-principles study

RSC Advances ◽  
2020 ◽  
Vol 10 (5) ◽  
pp. 2448-2452
Author(s):  
Lili Lian ◽  
Yan Liu ◽  
Da Li ◽  
Shuli Wei
Keyword(s):  
Phase Transition ◽  
High Pressure ◽  
Electronic Properties ◽  
Structural Phase Transition ◽  
First Principles ◽  
Structural Phase ◽  
First Principles Study ◽  
Bonding Properties ◽  
First Principles Method

The structural phase transition, electronic properties, and bonding properties of antimony nitrides have been studied by using a first principles method.

Theoretical aspects in structural distortion and the electronic properties of lithium peroxide under high pressure

2018 ◽  
Vol 20 (14) ◽  
pp. 9488-9497 ◽  
Author(s):  
Pornmongkol Jimlim ◽  
Komsilp Kotmool ◽  
Udomsilp Pinsook ◽  
Suttichai Assabumrungrat ◽  
Rajeev Ahuja ◽  
...  
Keyword(s):  
Phase Transition ◽  
High Pressure ◽  
Electronic Properties ◽  
Structural Phase Transition ◽  
First Principles ◽  
Structural Phase ◽  
Structural Distortion ◽  
First Principles Calculations ◽  
Lithium Peroxide

The structural phase transition and electronic properties of Li2O2 under pressures up to 500 GPa have been investigated using first-principles calculations.

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