Article
Materials Science, Ceramics
V. I. Ivashchenko, P. E. A. Turchi, R. Shevchenko, Leonid Gorb, Jerzy Leszczynski
Summary: First-principles molecular dynamics simulations were used to generate samples of amorphous a-AlB2, a-AlBC, and a-AlBN alloys, which exhibited boron clustering and different structural characteristics. The phonon spectra of the amorphous samples displayed broad bands, while the alloys varied in hardness, ideal tensile strength, Debye temperature, and fracture toughness. Predictions suggest that crystalline AlB2 is closer to a brittle material, while the amorphous alloys are expected to exhibit ductile behavior and semiconductor properties with a mobility gap in a certain range.
JOURNAL OF NON-CRYSTALLINE SOLIDS
(2022)
Article
Materials Science, Multidisciplinary
Ayseguel Ozlem Karacaoglu, Murat Durandurdu
Summary: The amorphous form of silicon tetraboride is found energetically more favorable than the crystal form. Si atoms tend to structure in higher coordinated motifs in the amorphous configuration compared to the crystal.
MATERIALS CHEMISTRY AND PHYSICS
(2021)
Article
Materials Science, Ceramics
Murat Durandurdu
Summary: A boron-substituted amorphous graphite network with a layered structure primarily composed of hexagonal rings is generated through first principles molecular dynamics simulation. The network exhibits a semimetal character and has mechanical properties comparable to graphite or amorphous graphite.
JOURNAL OF NON-CRYSTALLINE SOLIDS
(2022)
Article
Physics, Condensed Matter
Lei Kang, Leng Chen
Summary: The local structure of liquid Sb2Te exhibits a mixed bonding geometry with an increase in Sb-Sb bonds and a decrease in Sb-Te bonds, while the amorphous Sb2Te is predominantly in an octahedral environment. This structural transformation involves the formation of homopolar bonds and the breaking of heteropolar bonds in the liquid phase, and an increase in the fraction of octahedron and a decrease in average coordination number in the amorphous phase. The octahedral geometry in both crystalline and amorphous Sb2Te enhances the local structural similarity, facilitating rapid low-energy crystallization.
JOURNAL OF PHYSICS-CONDENSED MATTER
(2021)
Article
Materials Science, Multidisciplinary
Yeonghun Lee, Yaoqiao Hu, Dongwook Kim, Suman Datta, Kyeongjae Cho
Summary: In this study, a new method was developed to predict carrier mobility in amorphous semiconductors using first-principles calculations, and the validity of this method was confirmed through quantitative comparisons with experimental data. Localization analysis provided further insights into the distinct features between amorphous metal oxides and amorphous silicon.
Article
Chemistry, Physical
K. C. Bhamu, Jin Suk Chung, Sung Gu Kang
Summary: This study investigates the dehydrogenation of liquid organic hydrogen carrier, 1,1,6,6-tetracyclohexylhexane, using various DFT-based approaches. The results show that BN substitution can decrease the dehydrogenation energy and influence the energy barrier for dehydrogenation, indicating a change in the chemical reactivity of LOHC.
INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
(2023)
Article
Materials Science, Ceramics
Evelyne Martin, Guido Ori, Thuy-Quynh Duong, Mauro Boero, Carlo Massobrio
Summary: In this study, the AEMD/FPMD method was used to investigate the thermal conductivity of amorphous SiO2, showing a decrease in thermal conductivity for sizes smaller than 10 nm. This behavior is similar to that observed in previous studies on amorphous chalcogenides, indicating a general feature of disordered networks rather than a specific characteristic of a particular class of systems.
JOURNAL OF NON-CRYSTALLINE SOLIDS
(2022)
Article
Materials Science, Multidisciplinary
Bruno Focassio, Gabriel R. Schleder, Felipe Crasto de Lima, Caio Lewenkopf, Adalberto Fazzio
Summary: Through simulations, it was found that amorphous Bi2Se3 has a reduced energy gap and its stability is influenced by defective environments. Additionally, topologically trivial surface states similar to standard helical topological states were identified in amorphous Bi2Se3.
Article
Materials Science, Multidisciplinary
Wenyi Ding, Min Zhang, Zhizhong Jiang, Mingjie Zheng, Wangli Huang
Summary: In this work, the dissolution, diffusion, bonding, and charging behavior of steel alloy elements in liquid lead-lithium (PbLi) were investigated using first principles molecular dynamics simulations. The study revealed the dissolution order of different alloy elements and the bonding between oxygen atoms and lead-lithium. These findings provide important information for understanding the corrosion behavior of advanced RAFM steel in liquid PbLi.
JOURNAL OF NUCLEAR MATERIALS
(2022)
Article
Materials Science, Multidisciplinary
Minghui Wang, Fangling Yang, Yuqi Chen, Tao Gao, Jianjun Wei, Zongbiao Ye, Fujun Gou
Summary: The diffusion behavior of hydrogen on tin-covered tungsten surfaces was studied using density functional theory. It was found that tin atoms strongly adsorb on the tungsten surface and can reduce the diffusion energy barriers of hydrogen, making diffusion easier. However, the coverage of tin has little impact on the diffusion of hydrogen in the sub-surface of tungsten.
JOURNAL OF NUCLEAR MATERIALS
(2023)
Article
Chemistry, Physical
Swayam Kesari, Brahmananda Chakraborty, A. K. Rajarajan, Antara Vaidyanathan, Rekha Rao
Summary: Compounds with polymorphism at ambient conditions exhibit interesting structural transitions under different thermodynamic conditions. Gd2Si2O7 is a silicate that shows polymorphism at ambient conditions, with significant structural changes at high pressures leading to different phases.
JOURNAL OF ALLOYS AND COMPOUNDS
(2022)
Article
Chemistry, Multidisciplinary
Thuy-Quynh Duong, Assil Bouzid, Carlo Massobrio, Guido Ori, Mauro Boero, Evelyne Martin
Summary: By using a first-principles approach to calculate the thermal conductivity of amorphous GST, this study reveals size effects and a strong size dependence of thermal conductivity at the nanoscale, which are expected to underpin the development of PCM-based device applications.
Article
Geochemistry & Geophysics
Luis E. Gonzalez, David J. Gonzalez
Summary: We studied the evolution of liquid Fe's structural and dynamic properties under different pressures using ab-initio molecular dynamics technique. The calculated static structure matches well with experimental data, indicating the presence of a local icosahedral short-range order in the liquid. The dynamic structure reveals two modes for all pressures, which can be related to the double-peak structure in the Fourier spectra of velocity autocorrelation functions. Our findings also show the existence of transverse acoustic excitation modes and changes in the electronic density of states with increasing pressure. Transport coefficients like self-diffusion, shear viscosity, and adiabatic sound velocity are compared with experimental data.
JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH
(2023)
Article
Multidisciplinary Sciences
Giuseppe Muscas, Robert Johansson, Sebastian George, Martina Ahlberg, Dimitri Arvanitis, Rajeev Ahuja, Ralph H. Scheicher, Petra E. Jonsson
Summary: In this study, the detailed structure of amorphous Fe(1-X)ZrX alloys with different compositions was explored using atomistic simulations and experimental characterisation. The local atomic arrangements were investigated through various methods such as radial-and angular-distribution functions and Voronoi tesselation. A model based on the radial distribution functions was used to fit the experimental EXAFS data, providing a simple yet accurate description of the atomic structures for different compositions. This approach improves the understanding of structure-property relationships and facilitates the development of amorphous alloys with tailored functional properties.
SCIENTIFIC REPORTS
(2023)
Article
Physics, Multidisciplinary
Xiao-Yan Liu, Lei Wang, Yi Tong
Summary: This study investigates the electronic structure and opto-electronic characteristics of ultra-thin amorphous carbon films at different densities and temperatures using density functional theory and molecular dynamic simulations. The results show that density has a significant influence on these aspects, while temperature has a weak influence. Furthermore, the transmittance of ultra-thin amorphous carbon films can be altered by adjusting the volume ratio of sp(2) to sp(3) bonding.