Article
Energy & Fuels
Peixin Yang, Ping Liu, Saad Ullah, Jiaming Wang, Linlin Liu, Shi-E Yang, Haizhong Guo, Lingrui Wang, Yongsheng Chen
Summary: This study investigates the relationship between phase stability and bandgap width of CsPb(I1-xBrx)(3) perovskite materials in humid environments, and their impact on power conversion efficiency. The results show that in the 4-T formation, CsPbBr3/Si TSCs have the potential to achieve PCE above 28.5%.
Article
Chemistry, Physical
Demetrio Scelta, Matteo Ceppatelli, Roberto Bini, Anna Pakhomova, Gaston Garbarino, Mohamed Mezouar, Mario Santoro
Summary: Experimental investigations were conducted on the high temperature transformation of amorphous polymeric carbon monoxide (pCO) in the pressure range of 47-120 GPa. The results showed that the decomposition of a-pCO into CO2 and likely a mixture of amorphous CxOy suboxides and amorphous carbon occurred, supporting the theoretical understanding. It was also found that the decomposition was strongly pressure-dependent with a steep pressure-temperature kinetic barrier.
JOURNAL OF CHEMICAL PHYSICS
(2023)
Article
Geochemistry & Geophysics
Hans-Joachim Massonne, Thomas Fockenberg
Summary: Melting experiments with phengite-bearing eclogite and psammopelitic rock powder yielded solidus temperatures at different pressures and compositions. Melts from subducted oceanic crust are unlikely but melange diapirs may partially melt in the mantle wedge, contributing to magmatic arcs.
EARTH AND PLANETARY SCIENCE LETTERS
(2022)
Article
Geochemistry & Geophysics
Anton Shatskiy, Ivan V. V. Podborodnikov, Anton V. V. Arefiev, Konstantin D. D. Litasov
Summary: Inclusions in mantle minerals and xenoliths from kimberlites derived from deep depths showed great variations in composition. The stability range of these inclusions remains unclear. New experimental data on the KCl-CaCO3-MgCO3 system obtained at 3 GPa show the eutectic type of phase relations. The melting reactions of KCl-bearing carbonated eclogite at different pressures and depths are also identified.
Article
Computer Science, Information Systems
Jia-Hao Lin, Hung-Wei Wu, Wei-Chen Tien, Cheng-Yuan Hung, Shih-Kun Liu
Summary: The effects of chamber pressures on the passivation layer of hydrogenated nano-crystalline silicon mixed-phase thin film were studied using microwave annealing. By controlling the chamber pressures of VHFPECVD and enhancing the film quality with MWA, a high-quality nc-Si:H thin film was successfully achieved, showing promising potential for thin-film solar-cell applications.
Article
Nanoscience & Nanotechnology
Vo Van Hoang
Summary: The melting of two-dimensional hexagonal SiC nanoribbons was studied using molecular dynamics simulations. It was found that in the initial stage of melting, liquid-like atoms occur first in the edge region, and further heating leads to the homogeneous occurrence and growth of liquid-like atoms throughout the models.
PHYSICA E-LOW-DIMENSIONAL SYSTEMS & NANOSTRUCTURES
(2022)
Article
Geosciences, Multidisciplinary
Anton Shatskiy, Altyna Bekhtenova, Ivan Podborodnikov, Anton Arefiev, Yulia G. Vinogradova, Konstantin D. Litasov
Summary: The study examined the interaction of natural eclogite with synthetic hydrous carbonate melts under varying conditions, revealing different mineral evolution outcomes, and indicating that hydrous K-and Na-K-carbonatite melts can coexist with eclogite at depths in the mantle, leading to different mineral assemblages.
Article
Physics, Multidisciplinary
Yu D. Fomin, I. Danilov, E. L. Gromnitskaya
Summary: We conducted ultrasonic measurements on propylene glycol to determine its density and bulk modulus at room temperature and liquid nitrogen temperature under pressures up to 1.4 GPa. Molecular dynamics simulations using the COMPASS and Charmm force fields were performed. Our results show that the COMPASS force field accurately reproduces the experimental data. We also observed that the number of hydrogen bonds in the system remains constant regardless of pressure.
Article
Chemistry, Multidisciplinary
Larissa Q. Huston, Alois Lugstein, Guoyin Shen, David A. Cullen, Bianca Haberl, Jim S. Williams, Jodie E. Bradby
Summary: High-pressure synthesis can create promising silicon allotropes, some of which have direct band gaps under tensile strain while others have narrow band gaps and good absorption properties. This study has discovered a new pressure-temperature pathway for producing silicon nanowires with transformative properties, opening up new possibilities for nanomaterial synthesis.
Article
Chemistry, Physical
Xiaoning Wang, Baoyun Wang, Dayong Tan, Wansheng Xiao, Maoshuang Song
Summary: The compression behavior of zircon-type DyVO4 has been investigated under high pressures up to 36.4 GPa using angle-dispersive X-ray diffraction. The study revealed a sequential zircon-scheelite-fergusonite phase transformation, with the scheelite-fergusonite transformation being sensitive to nonhydrostatic conditions.
JOURNAL OF ALLOYS AND COMPOUNDS
(2021)
Article
Thermodynamics
Branson W. Davis, Jordi Poblador-Ibanez, William A. Sirignano
Summary: Numerical analysis of a shear layer between cool liquid n-decane hydrocarbon and hot oxygen gas at supercritical pressures reveals a well-defined phase equilibrium can be established, with nearly constant results within the laminar flow region and thick diffusion layers supporting continuum theory and phase equilibrium around the liquid-gas interface. Net mass flux shifts across the interface as pressure is increased, with net vaporization at low pressures and net condensation at high pressures. Similar one-dimensional profiles are observed at high Reynolds numbers, indicating validity of the boundary layer approximation and similarity in both phases.
INTERNATIONAL JOURNAL OF HEAT AND MASS TRANSFER
(2021)
Article
Materials Science, Multidisciplinary
M. D. Mihai, D. Iancu, E. Zarkadoula, R. A. Florin, Y. Tong, Y. Zhang, W. J. Weber, G. Velisa
Summary: Systematic investigations of electronic energy loss effects on pre-existing defects in crystalline silicon are crucial to ensure the reliability of ionizing irradiation for annealing pre-existing defects, which is important for the fabrication of Si-based devices.
Article
Physics, Multidisciplinary
Tian-Shou Liang, Peng-Peng Shi, San-Qing Su, Zhi Zeng
Summary: In this work, a deep learning architecture was proposed to accurately identify the solid and liquid phases of crystalline materials based on atomic trajectories. The method achieved high accuracy in classifying solid-liquid atoms during phase transition processes and was not significantly affected by temperature. The study revealed the close correlation between atomic behaviors and physical states, suggesting the existence of an undiscovered physical quantity implicated in atomic behaviors.
Article
Physics, Multidisciplinary
Thomas B. Shiell, Li Zhu, Brenton A. Cook, Jodie E. Bradby, Dougal G. McCulloch, Timothy A. Strobel
Summary: Bulk, highly oriented, crystalline 4H hexagonal silicon (4H-Si) was successfully synthesized through a metastable crystalline transition pathway by heating the single-crystalline Si-24 allotrope. The resulting 4H-Si crystallites exhibit an orientation relationship with the Si-24 crystals, indicating a structural relationship between the two phases. Optical absorption measurements confirm that 4H-Si has an indirect band gap near 1.2 eV, in agreement with first principles calculations.
PHYSICAL REVIEW LETTERS
(2021)
Article
Chemistry, Physical
Bharti, Debabrata Deb
Summary: We investigated the ordering phenomena in two-dimensional liquid crystals over a one-dimensional periodic substrate using molecular dynamics simulations. The periodicity of the substrate plays a crucial role in the phase transitions of the liquid crystal system, with small periodicity stabilizing a disordered phase, intermediate periodicity leading to a modulated smectic phase, and larger periodicity causing the system to return to a nematic phase similar to a free system without substrate.
PHYSICAL CHEMISTRY CHEMICAL PHYSICS
(2022)
Article
Physics, Fluids & Plasmas
V. S. Filinov, P. R. Levashov, A. S. Larkin
Summary: The quantum path integral Monte Carlo approach has been applied to the entropy difference calculations for strongly coupled degenerated uniform electron gas (UEG), providing data on pressure, internal energy, and entropy change, which may be beneficial for density functional theory. Published by AIP Publishing under an exclusive license.
PHYSICS OF PLASMAS
(2021)
Article
Physics, Multidisciplinary
V Filinov, P. Levashov, A. Larkin
Summary: A new path integral representation of the density matrix in the canonical ensemble at finite temperatures has been developed to address the interference effects of the Coulomb and exchange interactions of electrons, reducing the 'fermionic sign problem' in Monte Carlo simulations. The results obtained for pair distribution functions in plasma and uniform electron gas demonstrate short-range quantum ordering of electrons associated with exchange-correlation excitons in the literature. Comparisons with available literature also show that the short-range ordering does not significantly contribute to integral thermodynamic characteristics.
JOURNAL OF PHYSICS A-MATHEMATICAL AND THEORETICAL
(2022)
Article
Physics, Fluids & Plasmas
A. S. Larkin, V. S. Filinov, P. R. Levashov
Summary: This paper presents a single-momentum path integral Monte Carlo method adapted for simulations of the uniform electron gas, based on the combination of Wigner formalism and the path integral approach. By taking into account the exchange interaction between electrons and using the Gram determinants of the exchange matrix, the fermionic sign problem is significantly reduced and completely eliminated in coordinate-dependent variables, making it a valuable tool for studying thermodynamic properties.
PHYSICS OF PLASMAS
(2021)
Article
Physics, Applied
M. A. Paramonov, D. V. Minakov, V. B. Fokin, D. V. Knyazev, G. S. Demyanov, P. R. Levashov
Summary: This study presents quantum molecular dynamics calculations of thermophysical properties of solid and liquid zirconium near the melting point and provides an overview of available experimental data. By comparing the simulation results with experiments, possible reasons for discrepancies are discussed. The study reveals a significant volume change and low enthalpy of fusion on melting, and observes underestimation of electrical resistivity in the simulations while the slope of resistivity temperature dependencies agrees with experiments. The calculations predict almost constant normal spectral emissivity in liquid zirconium.
JOURNAL OF APPLIED PHYSICS
(2022)
Article
Physics, Multidisciplinary
G. S. Demyanov, P. R. Levashov
Summary: In this work, we provide a step-by-step derivation of an angular-averaged Ewald potential suitable for numerical simulations of disordered Coulomb systems. The potential's coefficients are found using Euler-Maclaurin and Poisson summation formulas, and are represented as finite series containing derivatives of Jacobi theta functions. The effectiveness of the potential is demonstrated through the calculation of the Madelung constant for various crystal lattices.
JOURNAL OF PHYSICS A-MATHEMATICAL AND THEORETICAL
(2022)
Article
Mathematics
Alexander Larkin, Vladimir Filinov, Pavel Levashov
Summary: This paper investigates the uniform electron gas in a warm dense matter regime and reveals the presence of quantum tails and short-range order under non-ideal conditions.
Article
Physics, Fluids & Plasmas
A. S. Poliukhin, S. A. Dyachkov, A. A. Malyugin, P. R. Levashov
Summary: The discovery of material properties at extremes is crucial for the development of high energy density physics. Advanced experimental facilities, theories, and computations are needed for this purpose. The use of density functional theory (DFT) and path-integral Monte Carlo approaches have provided precise models for matter properties under extreme conditions. However, their practical usage is limited due to fundamental and computational constraints, and wide-range thermodynamic and transport models of plasma are required.
PHYSICS OF PLASMAS
(2023)
Article
Multidisciplinary Sciences
Vladimir Fokin, Dmitry Minakov, Pavel Levashov
Summary: The dynamic electrical conductivity of dense Zr plasma near melting is calculated using ab initio molecular dynamics and the Kubo-Greenwood formula. The influence of computational parameters and inner shell electrons on the results is thoroughly investigated. The convergence of the computations and comparison with experimental data are demonstrated.
Article
Computer Science, Interdisciplinary Applications
O. P. Shemyakin, P. R. Levashov, P. A. Krasnova
Summary: In this paper, the authors review the finite-temperature Thomas-Fermi model for a mixture of elements and describe the modifications made for the new version (1.5) of the code. The model is used to calculate thermodynamic properties of electrons in a mixture of elements. The modifications include adding density as an input parameter, changing the calculation of thermal energy, adding more thermodynamic functions in the output, providing the ability to plot isotherms and isochores in the graphical user interface, and making minor corrections.
COMPUTER PHYSICS COMMUNICATIONS
(2023)
Article
Physics, Multidisciplinary
V Filinov, P. Levashov, A. Larkin
Summary: The Wigner formulation of quantum mechanics is utilized to derive a new path integral representation of quantum density of states. A path integral Monte Carlo approach is developed for investigating the DOSs, internal energy, and spin-resolved radial distribution functions of a 2D system of strongly correlated soft-sphere fermions. The study examines and explains the peculiarities of DOSs and internal energy distributions depending on the softness of the potential and particle density, where the DOSs tend to a constant value at high densities, resembling an ideal 2D fermion system.
JOURNAL OF PHYSICS A-MATHEMATICAL AND THEORETICAL
(2023)
Article
Materials Science, Multidisciplinary
D. V. Minakov, M. A. Paramonov, G. S. Demyanov, V. B. Fokin, P. R. Levashov
Summary: In this study, the melting curves of hafnium and zirconium are obtained using quantum molecular dynamics calculations. The results show that the melting curves of both materials are consistent with experimental data within the error range. Additionally, we provide the first estimate of the melting curve of hafnium under ultra-high pressures.
Article
Physics, Applied
V. S. Dozhdikov, A. Yu. Basharin, P. R. Levashov
Summary: Amorphous carbon is obtained by quenching liquid carbon for the first time. Laser melting of graphite flakes on a diamond substrate allows liquid carbon to fall on cold diamond for rapid cooling. Diamond acts as a unique quenching medium for extremely high-temperature molten carbon.
Article
Physics, Fluids & Plasmas
G. S. Demyanov, P. R. Levashov
Summary: In this study, a correct expression for the one-component plasma energy is derived using the angular-averaged Ewald potential. The derived potential shows significant advantages in large-scale numerical simulations, offering a unified approach for determining the thermodynamic limit.
Article
Physics, Fluids & Plasmas
G. S. Demyanov, D. Knyazev, P. R. Levashov
Summary: In this paper, the continuous Kubo-Greenwood formula for calculating the dynamic Onsager coefficients and real part of dynamic electrical conductivity is presented. It is formulated as an integral over the whole energy range, unlike the usual formula which involves summation over discrete transitions between electron energy levels. The continuous formula includes smooth functions that can be plotted and analyzed, allowing for the contribution analysis of various parts of the electron spectrum to the obtained properties. The formula has been implemented in the parallel code CUBOGRAM and used to study the influence of technical parameters on simulation results for liquid aluminum.
Article
Physics, Fluids & Plasmas
Yaroslav Lavrinenko, Pavel R. Levashov, Dmitry Minakov, Igor Morozov, Ilya A. Valuev
Summary: The joint simulation method of WPMD-DFT is utilized to study warm dense deuterium, providing a more accurate representation of quantum effects compared to classical molecular dynamics and WPMD simulations. The method allows for studying nonadiabatic dynamics of electrons and ions in equilibrium and nonequilibrium states, being more accurate and efficient at high densities. Results obtained by WPMD-DFT for shock-compressed deuterium are compared with experimental data and other simulation approaches to validate its accuracy for further application in studying nonequilibrium states and relaxation processes.
