Nucleation and growth of islands in epitaxy is simulated using a continuum phase-field model. In addition to local density of adatoms, a local phase-field variable, varying in the real space, is introduced to describe the epitaxial islands. Evolution of this phase field is determined by a time-dependent Ginzburg-Landau-like equation coupled to a diffusive transport equation of adatoms. When applied to nucleation and growth of islands in the submonolayer regime, this model reproduces both the scaling laws of island density and experimental size and spatial distributions of islands. For island growth in the multilayer regime, this phase-field model reproduces mound structures consistent with experimental images concerned. Accurate coarsening and roughening exponents of the mounds are obtained in this model. Compared with atomic models and mean-field models, this model can provide a fine visualized morphology of islands at large space and time scales of practical engineering interests.
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http://dx.doi.org/10.1103/PhysRevE.69.021601 | DOI Listing |
ACS Appl Mater Interfaces
January 2025
School of Energy and Power Engineering, Huazhong University of Science & Technology, Wuhan, Hubei 430074, China.
Nanotechnology
January 2025
MME, Wright State University, 3640 Colonel Glenn Hwy, Lake Campus, 7600 Lake Drive, Lake Campus, Fairborn, Ohio, 45435, UNITED STATES.
Surface induced crystallization/amorphization of a Germanium-antimony-tellurium (GST) nanolayer is investigated using the phase field model. A Ginzburg-Landau (GL) equation introduces an external surface layer (ESL) within which the surface energy and elastic properties are properly distributed. Next, the coupled GL and elasticity equations for the crystallization/amorphization are solved.
View Article and Find Full Text PDFACS Appl Mater Interfaces
January 2025
School of Materials Science and Engineering, UNSW Sydney, NSW 2052, Australia.
Domain walls are quasi-one-dimensional topological defects in ferroic materials, which can harbor emergent functionalities. In the case of ferroelectric domain wall (FEDW) devices, an exciting frontier has emerged: memristor-based information storage and processing approaches. Memristor solid-state FEDW devices presented thus far, however predominantly utilize a complex network of domain walls to achieve the desired regulation of density and charge state.
View Article and Find Full Text PDFACS Energy Lett
December 2024
School of Materials Science and Engineering, Georgia Institute of Technology, Atlanta, Georgia 30332, United States.
Solid-state batteries (SSBs) with silicon anodes could enable improved safety and energy density compared to lithium-ion batteries. However, degradation arising from the massive volumetric changes of silicon anodes during cycling is not well understood in solid-state systems. Here, we use X-ray computed microtomography to reveal micro- to macro-scale chemo-mechanical degradation processes of silicon anodes in SSBs.
View Article and Find Full Text PDFNPJ Comput Mater
December 2024
Institute of Applied Mechanics, Friedrich-Alexander-Universität Erlangen-Nürnberg, Egerlandstr. 5, 91058 Erlangen, Germany.
Large deformations of soft materials are customarily associated with strong constitutive and geometrical nonlinearities that originate new modes of fracture. Some isotropic materials can develop strong fracture anisotropy, which manifests as modifications of the crack path. Sideways cracking occurs when the crack deviates to propagate in the loading direction, rather than perpendicular to it.
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