Article
Chemistry, Physical
Ashkan Shekaari, Mahmoud Jafari
Summary: The thermodynamic properties of phagraphene (PG) were calculated using the quasi-harmonic approximation and PBE level of density-functional theory. The results showed that PG exhibits high thermal stability and follows the classical limit at high temperatures.
MOLECULAR SIMULATION
(2022)
Article
Chemistry, Physical
Wilfried B. Holzapfel, Stefan Klotz
Summary: New data and evaluations provide a basis for the thermodynamic modeling of ice Ih, with the model accurately fitting experimental data and providing a basis for comparison with previous determinations.
JOURNAL OF CHEMICAL PHYSICS
(2021)
Article
Materials Science, Ceramics
O. O. Vasiliev
Summary: In this study, standard values of the thermodynamic properties of hexagonal tungsten disulfide 2H-WS2 at 298.15K were calculated from first principles, showing good agreement with experimental results and improving the reliability of the data. The findings suggest a need for more experimental studies of the phonon spectrum of 2H-WS2, especially in the Gamma -> K region. The heat capacity, entropy, and enthalpy values of tungsten disulfide are recommended for thermodynamic databases and practical applications.
POWDER METALLURGY AND METAL CERAMICS
(2021)
Article
Physics, Condensed Matter
Xinzhan Qin, Jian Zhao, Ran Wei, Yu Cao, Manchao He
Summary: Pyrophyllite's thermodynamic and thermoelastic properties at high temperatures are detailed, confirming its thermal expansion effect and discussing its elastic behaviors under various temperatures.
PHYSICA B-CONDENSED MATTER
(2022)
Article
Physics, Condensed Matter
Junyu Fan, Yan Su, Zhaoyang Zheng, Jijun Zhao
Summary: Research on the thermodynamic properties of several representative energetic materials at finite temperatures shows significant effects of temperature on lattice parameters and thermal expansion coefficients, with TATB exhibiting higher expansion rate in the inter-layer direction. The calculated heat capacities accurately reproduce experimental trends and provide rich information for thermodynamic data.
JOURNAL OF PHYSICS-CONDENSED MATTER
(2021)
Article
Crystallography
Touwen Fan, Lan Lin, Houjiang Liang, Yuhong Ma, Yuwei Tang, Te Hu, Zixiong Ruan, Dongchu Chen, Yuanzhi Wu
Summary: In this study, the stability, mechanical and thermodynamic properties of Al11RE3 intermetallics (RE = Sc, Y and lanthanide La-Lu) were investigated using first-principles and Debye model calculations. It was found that the Al11RE3 intermetallics were stable, with negative formation enthalpies. The mechanical properties of these intermetallics, such as Young's modulus and shear modulus, were significantly greater than that of aluminum, indicating their potential to enhance the mechanical property of aluminum alloys. The Al11RE3 intermetallics also exhibited improved thermostability compared to aluminum due to their lower Gibbs free energy, higher entropy, and constant volume-specific heat at finite temperatures. The findings of this study can contribute to the design of high-performance, heat-resistant aluminum alloys.
Article
Chemistry, Multidisciplinary
Markos Poulos, Stefanos Giaremis, Joseph Kioseoglou, John Arvanitidis, Dimitris Christofilos, Sotirios Ves, Markus P. Hehlen, Neil L. Allan, Chris E. Mohn, Konstantinos Papagelis
Summary: Inelastic neutron scattering measurements of Y3Al5O12 were presented, with comparison of neutron-weighted phonon density-of-states and optical phonon frequencies to atomistic calculations within the Quasi-Harmonic Approximation. The phonon-related thermodynamic and elastic properties calculated within the QHA showed excellent agreement with experimental data.
JOURNAL OF PHYSICS AND CHEMISTRY OF SOLIDS
(2022)
Article
Materials Science, Ceramics
Jieqiang Jiang, Zuhao Shi, Arramel, Jinyong Zhang, Tengfei Deng, Neng Li
Summary: This article investigates the temperature-dependent elastic and thermodynamic properties of (Zr0.5Hf0.5)C and reveals the weakening of the covalent characters at high temperatures. HfC exhibits the highest bulk modulus and lowest thermal expansion among the studied materials. (Zr0.5Hf0.5)C shows comparable shear and Young's modulus performance to HfC when T > 1000 K and has the highest anisotropy. The lattice thermal conductivity decreases with increasing temperature for ZrC, HfC, and (Zr0.5Hf0.5)C, with (Zr0.5Hf0.5)C having the smallest lattice thermal conductivity.
JOURNAL OF THE AMERICAN CERAMIC SOCIETY
(2023)
Article
Materials Science, Multidisciplinary
Shimin Huang, Shuang Xu, Yurong Xu, Zixiang Zhou, Jun Li
Summary: This paper discusses the effects of carbon vacancies and dopants on the mechanical properties and thermodynamic properties of zirconium carbide. The results show that doping O and B atoms can improve the thermal conductivity, with ZrC0.75B0.25 exhibiting the highest thermal conductivity and ZrC0.75O0.25 showing the largest thermal expansion.
MATERIALS RESEARCH EXPRESS
(2021)
Article
Materials Science, Multidisciplinary
Mahfooz Alam, Appala Naidu Gandi
Summary: The temperature dependence of structural, mechanical, and thermodynamic properties of ?-TiAl is modeled using an extended quasi-harmonic approximation and first-principles calculations. The study suggests that further optimization of the degree of freedom in the unit cell improves the model accuracy of properties estimated following the quasi-harmonic approximation.
MODELLING AND SIMULATION IN MATERIALS SCIENCE AND ENGINEERING
(2023)
Article
Mathematics, Applied
Yves Benoist, Dominique Hulin
Summary: We have proven that a quasi-isometric map, or more broadly a coarse embedding, between pinched Hadamard manifolds is at a bounded distance from a unique harmonic map.
JOURNAL OF THE EUROPEAN MATHEMATICAL SOCIETY
(2021)
Article
Physics, Condensed Matter
Abdallah Qteish, Tariq Ayasrah, Abdullah I. Al-Sharif, Iyad I. Al-Qasir
Summary: In this study, it is further confirmed that the validity range of the quasi-harmonic approximation (QHA) can be extended by explicitly calculating the Helmholtz free energy over an appropriate volume range. Accurate QHA calculations were performed for the thermal properties of the B1 phase of CaO and SrO over a wide temperature range, as well as their B1-B2 phase boundaries in the pressure- temperature space. The validity range of the QHA is consistent with the bond ionicity in MgO, CaO and SrO.
PHYSICA B-CONDENSED MATTER
(2023)
Article
Chemistry, Physical
M. M. Conde, M. Rovere, P. Gallo
Summary: Direct coexistence simulations have revealed the spontaneous growth of a new ice doped phase and the formation of a brine rejection phase in different types of ice in contact with a NaCl aqueous solution. The preferential incorporation of ions into the ice lattice and the inclusion mechanisms depend on the crystalline structure of each ice. This work demonstrates the inclusion of Cl- and Na+ ions in ice from salt using molecular dynamics simulation.
PHYSICAL CHEMISTRY CHEMICAL PHYSICS
(2021)
Article
Chemistry, Physical
Jyotirmoy Ghosh, Gaurav Vishwakarma, Subhadip Das, Thalappil Pradeep
Summary: This study investigates the dissociation of formaldehyde hydrate under ultrahigh vacuum conditions, leading to a new and facile route for the crystallization of ice I-h with lower activation energy. The findings suggest potential implications for cometary and prebiotic science in interstellar environments.
JOURNAL OF PHYSICAL CHEMISTRY C
(2021)
Article
Thermodynamics
Javier Jofre, Aimen E. Gheribi, Jean-Philippe Harvey
Summary: This work presents a new formalism for the evaluation of thermodynamic properties of compounds and solid solution end-members. The method is based on the Debye approximation and is fully thermodynamically self-consistent. The formalism takes into account various energetic contributions and can accurately reproduce experimental data. The article emphasizes the analysis and description of anharmonic vibrational contributions and predicts self-consistent thermodynamic and thermo-physical properties.
CALPHAD-COMPUTER COUPLING OF PHASE DIAGRAMS AND THERMOCHEMISTRY
(2023)
Article
Chemistry, Physical
Alec Wills, Marivi Fernandez-Serra
Summary: The study found that non-converged simulation parameters and small changes in solution density can significantly affect the balance between different ion pair configurations. The thermodynamic stability of contact and solvent-separated ion pairs is highly sensitive to the dielectric properties of the simulation model. Classical models are robust in estimating contact ion pair stability, while density functional theory-based models are more variable.
JOURNAL OF CHEMICAL PHYSICS
(2021)
Article
Chemistry, Physical
Alberto Torres, Luana S. Pedroza, Marivi Fernandez-Serra, Alexandre R. Rocha
Summary: The study evaluates errors in density functional theory simulations of water, finding strong dependence of dynamic properties on simulation size and timescale, while structural properties are less dependent on system size.
JOURNAL OF PHYSICAL CHEMISTRY B
(2021)
Article
Chemistry, Multidisciplinary
Carlos P. Herrero, Rafael Ramirez
Summary: The study investigates the isotopic effects in graphane, showing notable influences on material properties when substituting different isotopic atoms at low temperatures. Path-integral molecular dynamics simulations reveal the impact of isotopic atoms on equilibrium variables, providing important insights for material research.
JOURNAL OF PHYSICS AND CHEMISTRY OF SOLIDS
(2021)
Article
Chemistry, Physical
Carlos P. Herrero, Jose A. Verges, Rafael Ramirez
Summary: In this study, the hydrogen dynamics on a graphene sheet is investigated in the presence of carbon vacancies. By conducting molecular dynamics simulations and analyzing the statistical data, it is found that hydrogen atoms can form stable C-H bonds with carbon atoms near vacancies on graphene. The diffusion of a single hydrogen atom on graphene exhibits stochastic jumps with an effective barrier of approximately 0.40 eV. The presence of two hydrogen atoms close to a vacancy leads to lower jump frequencies, indicating strong correlations in their atomic dynamics.
Article
Chemistry, Multidisciplinary
Carlos P. Herrero, Rafael Ramirez
Summary: Nuclear quantum effects in 2D silicon carbide are investigated using path-integral molecular dynamics simulations. The results show appreciable quantum effects on the structural properties and discuss the bending and rippling at finite temperatures. This study provides insights into the elastic and mechanical properties of 2D SiC.
JOURNAL OF PHYSICS AND CHEMISTRY OF SOLIDS
(2022)
Article
Chemistry, Physical
Carlos P. Herrero, Rafael Ramirez, Gabriela Herrero-Saboya
Summary: We studied the mechanical properties of 3C-SiC under a wide range of pressures using molecular dynamics simulations. The simulation, based on an effective tight-binding Hamiltonian, showed good agreement with ab-initio density-functional-theory calculations. The results revealed the spinodal instability and metastability limits of the material as a function of temperature, providing insights into the behavior of crystalline semiconductors in unexplored regions of their phase diagrams.
Article
Physics, Condensed Matter
Carlos P. Herrero, Rafael Ramirez
Summary: The elastic properties and mechanical stability of graphene bilayers were studied by molecular dynamics simulations. It was found that the in-plane compression modulus of bilayer graphene decreases with increasing temperature and is higher than that of monolayer graphene. The influence of anharmonicity of the vibrational modes on the physical properties of bilayer graphene was also analyzed.
EUROPEAN PHYSICAL JOURNAL B
(2023)
Article
Materials Science, Multidisciplinary
Sebastian Dick, Marivi Fernandez-Serra
Summary: By utilizing an end-to-end differentiable implementation of the Kohn-Sham self-consistent field equations, the study introduces a highly accurate neural network-based exchange and correlation (XC) functional for electronic density. The research evaluates the model against various families of XC approximations and establishes a strong linear correlation between energy and density errors to define a new XC functional quality metric, improving the ranking of different approximations.
Article
Materials Science, Multidisciplinary
Carlos P. Herrero, Rafael Ramirez
Summary: This study investigates the quantum effects in structural and elastic properties of graphite using path-integral molecular dynamics simulations, showing that quantum motion is essential in accurately describing thermal expansion and elastic properties, with quantum corrections potentially exceeding 20% for some stiffness constants. The bulk modulus and Poisson's ratio are reduced by 4% and 19%, respectively, due to zero-point motion of the C atoms, with these quantum effects remaining significant at temperatures higher than 300 K.
Article
Materials Science, Multidisciplinary
R. Ramirez, C. P. Herrero
Article
Chemistry, Multidisciplinary
Shaobo Cheng, Vidushi Sharma, Altug S. Poyraz, Lijun Wu, Xing Li, Amy Marschilok, Esther S. Takeuchi, Kenneth J. Takeuchi, Marivi Fernandez-Serra, Yimei Zhu
