Despite the fact that its crystal state is thermodynamically stable, CuZr alloy is prone to form metastable glass at a high cooling rate. However, the confinement can induce nano-crystallization with a novel sandwich-like hierarchical structure consisting of pure Cu layers, pure Zr layers and mixed layers by conducting molecular dynamics simulations. The liquid-to-crystal transition temperature and interatomic repulsion softness display abnormal oscillations, instead of monotonous variation, as the wall-wall separation increases. When the confinement size is 10 Å and 12 Å, the transition temperature reaches a maximum, resulting from the pending new sandwich layer. The atomic movement and dynamical heterogeneity are demonstrated to play a vital role in the abnormal oscillation behavior of physical properties of the nano confined metallic glass. The sandwich-like structure can alter the Cu-Zr bond fraction, which eventually influences the liquid-to-crystal transition temperature and interatomic repulsion softness. Our findings provide a deep insight into the hierarchical nanostructures and its liquid-to-crystal transition characteristics under confinement at the atomic level.
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http://dx.doi.org/10.1039/c9cp02254f | DOI Listing |
J Chem Phys
September 2022
Cavendish Laboratory, Department of Physics, Maxwell Centre, University of Cambridge, J J Thomson Avenue, Cambridge CB3 0HE, United Kingdom.
Freezing of water is the most common liquid-to-crystal phase transition on Earth; however, despite its critical implications on climate change and cryopreservation among other disciplines, its characterization through experimental and computational techniques remains elusive. In this work, we make use of computer simulations to measure the nucleation rate (J) of water at normal pressure under different supercooling conditions, ranging from 215 to 240 K. We employ two different water models: mW, a coarse-grained potential for water, and TIP4P/ICE, an atomistic nonpolarizable water model that provides one of the most accurate representations of the different ice phases.
View Article and Find Full Text PDFPhys Rev E
November 2020
Institute of Physical Chemistry, RWTH Aachen University, 52056 Aachen, Germany.
The phase behavior of supersoft spheres is explored using solutions of ultralow cross-linked poly(N-isopropylacrylamide)-based microgels as a model system. For these microgels, the effects of the electric charges on their surfaces can be neglected and therefore only the role of softness on the phase behavior is investigated. The samples show a liquid-to-crystal transition at higher volume fraction with respect to both hard spheres and stiffer microgels.
View Article and Find Full Text PDFJ Chem Phys
August 2020
Materials Science Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA.
Machine learning force field (ML-FF) has emerged as a potential promising approach to simulate various material phenomena for large systems with ab initio accuracy. However, most ML-FFs have been used to study the phenomena relatively close to the equilibrium ground states. In this work, we have studied a far from equilibrium system of liquid to crystal Si growth using ML-FF.
View Article and Find Full Text PDFJ Phys Chem B
September 2019
Department of Chemistry and Biochemistry , University of Arkansas, 119 Chemistry Building , Fayetteville , Arkansas 72701 , United States.
The excess free energy of a liquid relative to an Einstein crystal reference state is calculated without going through a first-order phase transition. This is accomplished by going through an arrested glassy state to avoid a direct liquid to gas or liquid to crystal transition. The method is demonstrated by calculating the free energy difference between liquid water and ice Ih using the TIP4P and WAIL water models.
View Article and Find Full Text PDFPhys Chem Chem Phys
July 2019
Key Laboratory for Liquid-Solid Structural Evolution and Processing of Materials, Ministry of Education, Shandong University, Jinan 250061, People's Republic of China.
Despite the fact that its crystal state is thermodynamically stable, CuZr alloy is prone to form metastable glass at a high cooling rate. However, the confinement can induce nano-crystallization with a novel sandwich-like hierarchical structure consisting of pure Cu layers, pure Zr layers and mixed layers by conducting molecular dynamics simulations. The liquid-to-crystal transition temperature and interatomic repulsion softness display abnormal oscillations, instead of monotonous variation, as the wall-wall separation increases.
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