Quantifying Thermal Transport of High-Temperature Ceramics From First Principle Calculations

2011 ◽  
Author(s):  
Babak Kouchmeshky ◽  
Peter Kroll
Keyword(s):  
Thermal Transport ◽  
Dynamics Simulation ◽  
Ab Initio Molecular Dynamics ◽  
First Principle ◽  
Anisotropic Behavior ◽  
Phonon Modes ◽  
Virtual Testing ◽  
Crystalline Materials ◽  
First Principle Calculations ◽  
Refractory Ceramics

We provide virtual testing capabilities of materials at temperatures where actual testing encounters many and severe technical difficulties. Combining ab-initio molecular dynamics simulation and kinetic theory we compute and analyze thermal transport of refractory ceramics at (ultra-) high temperatures ranging from 1000K to 2200 K. Most of our results are agreeable with available experimental data, though we find and examine discrepancies in selected cases. Our approach also catches the anisotropic behavior in thermal transport of some (single crystalline) materials. Since contributions of individual phonon modes on thermal transport are quantified, we suggest avenues for control and design of thermal conductivity in these materials.

The static and dynamic magnetic properties of monolayer iron dioxide and iron dichalcogenides

RSC Advances ◽  
2016 ◽  
Vol 6 (38) ◽  
pp. 31758-31761 ◽  
Author(s):  
Mu Lan ◽  
Gang Xiang ◽  
Ya Nie ◽  
Dingyu Yang ◽  
Xi Zhang
Keyword(s):  
Magnetic Properties ◽  
Electronic Structures ◽  
Spin Dynamics ◽  
Dynamics Simulation ◽  
First Principle ◽  
Atomic Spin ◽  
First Principle Calculations ◽  
Mc Simulation

The electronic structures, and static and dynamic magnetic properties of monolayer iron dioxide and iron dichalcogenides are investigated using first-principle calculations in conjunction with MC simulation and atomic spin dynamics simulation.

Lattice Vibration, Heat Capacity and Vibration Entropy of Single-Layer Hexagonal-BN

2013 ◽  
Vol 669 ◽  
pp. 138-143
Author(s):  
Man Zhao ◽  
Fei Ma ◽  
Hai Bing Zheng ◽  
Dong Yang ◽  
Ke Wei Xu
Keyword(s):  
Heat Capacity ◽  
Lattice Vibration ◽  
Single Layer ◽  
Vibration Modes ◽  
First Principle ◽  
Frequency Range ◽  
Phonon Modes ◽  
Hydrogen Atoms ◽  
First Principle Calculations ◽  
Narrow Frequency Range

Abstract. The phonon spectrum of zigzag h-BN nanoribbons with the edges passivated by hydrogen atoms under tensile strain along the axis direction were calculated by first-principle calculations. It is found that the uniaxial strain can lead to a narrow frequency range of lattice vibration modes. But it hardly affects the two highest frequency modes due to the vibration of B-H or N-H bonds. In particular, the strain usually promotes the softening of phonon modes. It means that more phonons should be activated at a given temperature. This may result in the changes of thermal properties, such as, heat capacity and vibration entropy.

Development of Interatomic Potentials for FCC Metals Based on Lattice Inversion Method

2020 ◽  
Vol 993 ◽  
pp. 1057-1062
Author(s):  
Xian Bao Duan ◽  
Zhi Peng Zhang ◽  
Hui Zhen He ◽  
Bin Shan
Keyword(s):  
Cohesive Energy ◽  
Potential Model ◽  
Interatomic Potential ◽  
Dynamics Simulation ◽  
Inversion Method ◽  
Interatomic Potentials ◽  
First Principle ◽  
Fcc Metals ◽  
First Principle Calculations ◽  
Equilibrium Lattice Constant

Interatomic potential plays an important role in molecular dynamics simulation, which determines both the efficiency and accuracy of the simulations. Lattice inversion is a method which can be used to develop interatomic potential from first principle results directly. In present work, a robust potential model based on lattice inversion is proposed. Then the potential model is applied to develop interatomic potentials for eight common FCC metals. The cohesive energy curves calculated using first principle calculations can be well reproduced, which verifies the reliability of the developed potential. Additional physical properties, including equilibrium lattice constant and cohesive energy, elastic constants, are predicted and found reasonable agreement with corresponding first principle results.

Phonon thermal transport in a class of graphene allotropes from first principles

2018 ◽  
Vol 20 (23) ◽  
pp. 15980-15985 ◽  
Author(s):  
Xiuxian Yang ◽  
Zhenhong Dai ◽  
Yinchang Zhao ◽  
Sheng Meng
Keyword(s):  
Transport Equation ◽  
Transport Properties ◽  
First Principles ◽  
Thermal Transport ◽  
First Principle ◽  
First Principle Calculations ◽  
Thermal Transport Properties

Utilizing first principle calculations combined with the phonon Boltzman transport equation (PBTE), we systematically investigate the phonon thermal transport properties of α, β and γ graphyne, a class of graphene allotropes.

Combustion Driven by Fragment-based Ab Initio Molecular Dynamics Simulation

2019 ◽  
Author(s):  
Liqun Cao ◽  
Jinzhe Zeng ◽  
Mingyuan Xu ◽  
Chih-Hao Chin ◽  
Tong Zhu ◽  
...  
Keyword(s):  
Molecular Dynamics ◽  
Ab Initio ◽  
Large Scale ◽  
Methane Combustion ◽  
Combustion Method ◽  
Dynamics Simulation ◽  
Ab Initio Molecular Dynamics ◽  
Computational Time ◽  
Combustion Mechanism ◽  
Daily Lives

Combustion is a kind of important reaction that affects people's daily lives and the development of aerospace. Exploring the reaction mechanism contributes to the understanding of combustion and the more efficient use of fuels. Ab initio quantum mechanical (QM) calculation is precise but limited by its computational time for large-scale systems. In order to carry out reactive molecular dynamics (MD) simulation for combustion accurately and quickly, we develop the MFCC-combustion method in this study, which calculates the interaction between atoms using QM method at the level of MN15/6-31G(d). Each molecule in systems is treated as a fragment, and when the distance between any two atoms in different molecules is greater than 3.5 Å, a new fragment involved two molecules is produced in order to consider the two-body interaction. The deviations of MFCC-combustion from full system calculations are within a few kcal/mol, and the result clearly shows that the calculated energies of the different systems using MFCC-combustion are close to converging after the distance thresholds are larger than 3.5 Å for the two-body QM interactions. The methane combustion was studied with the MFCC-combustion method to explore the combustion mechanism of the methane-oxygen system.

scholarly journals A First-Principle Study of Monolayer Transition Metal Carbon Trichalcogenides

2021 ◽  
Author(s):  
Muhammad Yar Khan ◽  
Yan Liu ◽  
Tao Wang ◽  
Hu Long ◽  
Miaogen Chen ◽  
...  
Keyword(s):  
Phonon Dispersion ◽  
Magnetic Ordering ◽  
Dimensional Structure ◽  
First Principle ◽  
Two Dimensional ◽  
Biaxial Strain ◽  
Half Metallic ◽  
First Principle Calculations ◽  
Potential Applications ◽  
External Strain

AbstractMonolayer MnCX3 metal–carbon trichalcogenides have been investigated by using the first-principle calculations. The compounds show half-metallic ferromagnetic characters. Our results reveal that their electronic and magnetic properties can be altered by applying uniaxial or biaxial strain. By tuning the strength of the external strain, the electronic bandgap and magnetic ordering of the compounds change and result in a phase transition from the half-metallic to the semiconducting phase. Furthermore, the vibrational and thermodynamic stability of the two-dimensional structure has been verified by calculating the phonon dispersion and molecular dynamics. Our study paves guidance for the potential applications of these two mono-layers in the future for spintronics and straintronics devices.

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