scholarly journals State of Charge Dependent Ordered and Disordered Phases in a Li[Ni1/3Co1/3Mn1/3]O2 Cathode Material

2021 ◽  
Author(s):  
Chi Ho Lee ◽  
Byeongsun Jun ◽  
Seung Cheol Lee ◽  
Sang Uck Lee
Keyword(s):  
Phase Transition ◽  
Monte Carlo Simulation ◽  
Monte Carlo ◽  
Cathode Material ◽  
Structural Phase Transition ◽  
Cluster Expansion ◽  
Density Functional ◽  
Structural Phase ◽  
The State ◽  
State Of Charge

We systematically investigated the structural phase transition of Li[Ni1/3Co1/3Mn1/3]O2 (NCM) cathode material depending on the state of charge (SOC) using cluster expansion Monte Carlo simulation (CE-MCS) combined with density functional...

scholarly journals Two-Electron Reaction without Structural Phase Transition in Nanoporous Cathode Material

2012 ◽  
Vol 2012 ◽  
pp. 1-8 ◽  
Author(s):  
Tomoyuki Matsuda ◽  
Yutaka Moritomo
Keyword(s):  
Phase Transition ◽  
Cathode Material ◽  
Structural Phase Transition ◽  
Structural Phase ◽  
Discharge Process ◽  
Charge Capacity ◽  
High Charge ◽  
Valence States ◽  
X Ray Absorption ◽  
Charge Discharge

We investigated the charge/discharge properties, valence states, and structural properties of a nanoporous cathode materialLixMn[Fe(CN)6]0.83·3.5H2O. The film-type electrode ofLixMn[Fe(CN)6]0.83·3.5H2Oexhibited a high charge capacity(=128 mAh g-1)and a good cyclability (87% of the initial value after 100 cycles) and is one of the promising candidates for Li-ion battery cathode. X-ray absorption spectra near the Fe and Mn K-edges revealed that the charge/discharge process is a two-electron reaction; that is,MnII–NC–FeII,MnII–NC–FeIII, andMnIII–NC–FeIII. We further found that the crystal structure remains cubic throughout the charge/discharge process. The lattice constant slightly increased during the[FeII(CN)6]4-/[FeIII(CN)6]3-oxidization reaction while decreased during theMnII/MnIIIoxidization reaction. The two-electron reaction without structural phase transition is responsible for the high charge capacity and the good cyclability.

Janus monolayer of WSeTe, a new structural phase transition material driven by electrostatic gating

Nanoscale ◽  
2018 ◽  
Vol 10 (46) ◽  
pp. 21629-21633 ◽  
Author(s):  
Yajing Sun ◽  
Zhigang Shuai ◽  
Dong Wang
Keyword(s):  
Phase Transition ◽  
Density Functional Theory ◽  
Structural Phase Transition ◽  
Density Functional ◽  
Structural Phase ◽  
Density Functional Theory Calculations ◽  
Functional Theory ◽  
Electrostatic Gating ◽  
Phase Transition Kinetics

By density functional theory calculations, we show that the Janus monolayer of WSeTe has faster semiconductor–semimetal phase transition kinetics than MoTe2.

scholarly journals DFT Calculations of the Structural, Mechanical, and Electronic Properties of TiV Alloy Under High Pressure

Symmetry ◽  
2019 ◽  
Vol 11 (8) ◽  
pp. 972 ◽  
Author(s):  
Fang Yu ◽  
Yu Liu
Keyword(s):  
Phase Transition ◽  
High Pressure ◽  
Electronic Properties ◽  
Structural Phase Transition ◽  
Density Functional ◽  
Structural Phase ◽  
Applied Pressure ◽  
Functional Theory ◽  
The Density Functional Theory ◽  
Dimensionless Ratio

A calculation program based on the density functional theory (DFT) is applied to study the structural, mechanical, and electronic properties of TiV alloys with symmetric structure under high pressure. We calculate the dimensionless ratio, elastic constants, shear modulus, Young’s modulus, bulk modulus, ductile-brittle transition, material anisotropy, and Poisson’s ratio as functions of applied pressure. Results suggest that the critical pressure of structural phase transition is 42.05 GPa for the TiV alloy, and structural phase transition occurs when the applied pressure exceeds 42.05 GPa. High pressure can improve resistance to volume change, as well as the ductility and atomic bonding, but the strongest resistances to elastic and shear deformation occur at P = 5   GPa for TiV alloy. Furthermore, the results of the density of states (DOS) indicate that the TiV alloy presents metallicity. High pressure disrupts the structural stability of the TiV alloy with symmetry, thereby inducing structural phase transition.

Structural phase transition, electronic, elastic, and vibrational properties of LiAl intermetallic compound: insights from first-principles calculations

2017 ◽  
Vol 95 (8) ◽  
pp. 691-698
Author(s):  
Y. Mogulkoc ◽  
Y.O. Ciftci ◽  
G. Surucu
Keyword(s):  
Phase Transition ◽  
Density Of States ◽  
Structural Phase Transition ◽  
First Principles ◽  
Density Functional ◽  
Structural Phase ◽  
Type Structure ◽  
Vibrational Properties ◽  
First Principles Calculations ◽  
Electronic Band

Using the first-principles calculations based on density functional theory (DFT), the structural, elastic, electronic, and vibrational properties of LiAl have been explored within the generalized gradient approximation (GGA) using the Vienna ab initio simulation package (VASP). The results demonstrate that LiAl compound is stable in the NaTl-type structure (B32) at ambient pressure, which is in good agreement with the experimental results and there is a structural phase transition from NaTl-type structure (B32) to CsCl-type structure (B2) at around 22.2 GPa pressure value. The pressure effects on the elastic properties have been discussed and the elastic property calculation indicates that the elastic instability could provide a phase transition driving force according to the variations relation of the elastic constant versus pressure. To gain further information about this, we also have investigated the other elastic parameters (i.e., Zener anisotropy factor, Poisson’s ratio, Young’s modulus, and isotropic shear modulus). The electronic band structure, total and partial density of states, phonon dispersion curves, and one-phonon density of states of B2 and B32 phases are also presented with results.

MONTE CARLO STUDY ON THE STRUCTURAL PHASE TRANSITION IN GdMg ALLOY

2003 ◽  
Vol 14 (05) ◽  
pp. 613-620
Author(s):  
S. CHITRA ◽  
K. P. N. MURTHY ◽  
K. RAMACHANDRAN
Keyword(s):  
Phase Transition ◽  
Solid Solution ◽  
Monte Carlo ◽  
Structural Phase Transition ◽  
Cohesive Energy ◽  
Structural Phase ◽  
Monte Carlo Study ◽  
Experimental Results

The average cohesive energy of the GdMg solid solution for various composition from x=0.10 to 0.90 has been worked out by simulation at 300 K, using Monte Carlo (MC) technique and was found that at x=0.58 there is a structural phase transition. This is compared with the available experimental results and was discussed.

The first-order structural phase transition of YSb

2010 ◽  
Vol 88 (8) ◽  
pp. 591-596
Author(s):  
Hongzhi Fu ◽  
WenFang Liu ◽  
Tao Gao
Keyword(s):  
Phase Transition ◽  
Structural Phase Transition ◽  
Density Functional ◽  
Theoretical Calculations ◽  
Structural Phase ◽  
Density Functional Theory Method ◽  
Generalized Gradient ◽  
First Order ◽  
Thermal Expansion Coefficients ◽  
Increasing Temperature

The high-pressure induced phase transition of YSb has been studied using the density functional theory method within the generalized gradient approximation. It was found that the first-order structural phase transition began to occur at 30.8 GPa, agreeing well with available experiments and theoretical calculations. In this phase transition, we do not find changes in the heat capacity and thermal expansion coefficients at lower and higher temperature, but the transition pressures decrease with temperature. The bulk modulus and Debye temperature decrease with increasing temperature, while they increase with increasing pressure. Also, the density of states and band structure of these two compounds with B1 and B2 structures have been presented and analyzed.

STRUCTURAL PHASE TRANSITION INDUCED BY PRESSURE IN THE ORDERED ALLOY FeRh

2005 ◽  
Vol 19 (21) ◽  
pp. 3389-3395 ◽  
Author(s):  
M. RAJAGOPALAN
Keyword(s):  
Phase Transition ◽  
Structural Phase Transition ◽  
First Principles ◽  
Density Functional ◽  
Structural Phase ◽  
Ferromagnetic State ◽  
Ambient Conditions ◽  
Density Functional Calculation ◽  
Antiferromagnetic Ground State ◽  
The One

First-principles density functional calculation of the total energy as a function of volume has been performed by the TB-LMTO approach for the ordered alloy FeRh in the anti-ferromagnetic state. We find that FeRh undergoes a structural phase transition from NaCl -type to tetragonal-type structure around 20.3 GPa which is in best agreement with the recent experimental observation. The calculations show that the energy of the antiferromagnetic ground state is lower than the one for the ferromagnetic state at ambient conditions.

Pressure-induced Structural Phase Transition of Carbon Nanotubes into New Nanostructured Carbon Solids

2009 ◽  
Vol 1204 ◽  
Author(s):  
Masahiro Sakurai ◽  
Susumu Saito
Keyword(s):  
Phase Transition ◽  
Carbon Nanotubes ◽  
Molecular Dynamics ◽  
Structural Phase Transition ◽  
Density Functional ◽  
Local Density ◽  
Structural Phase ◽  
Tight Binding ◽  
Dynamics Simulation ◽  
Nanotube Bundles

AbstractWe study pressure-induced structural phase transition of carbon nanotubes using the constant-pressure tight-binding molecular-dynamics simulation. The systems studied are nanotube bundles composed of (6,6) armchair nanotube and/or (7,4) chiral nanotube, which are reported to be the nanotubes relatively abundant in experimentally purified sample. We find that the nanotube bundles transforms into a new phase that consist of graphitic ribbons and diamond blocks, “graphitic nanoribbon solid”. It is also found that sp3-rich phases obtained from the armchair nanotubes possess an anisotropic network and have high hardness which is comparable to that of cubic diamond. In the case of the bundles containing chiral nanotubes, on the other hand, amorphous diamond phase is obtained. Based on the local-density approximation in the density-functional theory, we also investigate the energetics and electronic structure of some of new carbon phases obtained in the molecular-dynamics study.

scholarly journals Arrangement in La1/3NbO3 Obtained by First-Principles Density Functional Theory with Cluster Expansion and Monte Carlo Simulation

2020 ◽  
Vol 124 (18) ◽  
pp. 9746-9754
Author(s):  
Zijian Yang ◽  
Robyn E. Ward ◽  
Naoto Tanibata ◽  
Hayami Takeda ◽  
Masanobu Nakayama ◽  
...  
Keyword(s):  
Density Functional Theory ◽  
Monte Carlo Simulation ◽  
Monte Carlo ◽  
Cluster Expansion ◽  
First Principles ◽  
Density Functional ◽  
Functional Theory
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