Nano-patterning of surfaces by ion beam sputtering: numerical study of the anisotropic damped Kuramoto-Sivashinsky equation.
A numerical approach is presented for amodel describing the pattern formation by ion beam sputtering on a material surface. This process is responsible for the appearance of unexpectedly organized patterns, such as ripples, nanodots, and hexagonal arrays of nanoholes. A numerical analysis of preexis...
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| Tipo de recurso: | tesis de maestría |
| Estado: | Versión publicada |
| Fecha de publicación: | 2015 |
| País: | Brasil |
| Institución: | Universidade do Estado do Rio de Janeiro (UERJ) |
| Repositorio: | Biblioteca Digital de Teses e Dissertações da UERJ |
| Idioma: | inglés |
| OAI Identifier: | oai:www.bdtd.uerj.br:1/11718 |
| Acceso en línea: | http://www.bdtd.uerj.br/handle/1/11718 |
| Access Level: | acceso abierto |
| Palabra clave: | Mechanics Engineering Sputtering Finite-difference method Kuramoto-Sivashinsky equation Engenharia Mecânica Método das diferenças finitas equação de Kuramoto-Sivashinsky CNPQ::ENGENHARIAS::ENGENHARIA MECANICA |
| Sumario: | A numerical approach is presented for amodel describing the pattern formation by ion beam sputtering on a material surface. This process is responsible for the appearance of unexpectedly organized patterns, such as ripples, nanodots, and hexagonal arrays of nanoholes. A numerical analysis of preexisting patterns is proposed to investigate surface dynamics, based on a model resumed in an anisotropic damped Kuramoto-Sivashinsky equation, in a two dimensional surface with periodic boundary conditions. While deterministic, its highly nonlinear character gives a rich range of results, making it possible to describe accurately different patterns. A finite-difference semi-implicit time splitting scheme is employed on the discretization of the governing equation. Simulations were conducted with realistic coefficients related to physical parameters (anisotropies, beam orientation, diffusion). The stability of the numerical scheme is analyzed with time step and grid spacing tests for the pattern evolution, and the Method ofManufactured Solutions has been used to verify the scheme. Ripples and hexagonal patterns were obtained from amonomodal initial condition for certain values of the damping coefficient, while spatiotemporal chaos appeared for lower values. The anisotropy effects on pattern formation were studied, varying the angle of incidence. |
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