The mesoscopic modeling of laser ablation
Autor(a) principal: | |
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Data de Publicação: | 1999 |
Outros Autores: | , |
Tipo de documento: | Artigo |
Idioma: | eng |
Título da fonte: | Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos) |
Texto Completo: | http://hdl.handle.net/1822/3530 |
Resumo: | It is common to look at the atomic processes of removal of atoms or ions from surfaces. At this microscopic scale, one has to understand which surface ions are involved, which excited states are created, how electrons are transferred and scattered, and how the excitation leads to ion removal. It is even more common to look at continuum models of energy deposition in solids, and at the subsequent heat transfer In these macroscopic analyses, thermal conduction is combined with empirical assumptions about surface binding. Both these pictures are useful, and both pictures have weaknesses. The atomistic pictures concentrate on relatively few atoms, and do not recognize structural features or the energy and carrier fluxes on larger scales. The continuum macroscopic models leave out crystallographic information and the interplay of the processes with high nonequilibrium at smaller scales. Fortunately, there is a middle way: mesoscopic modeling, which both models the key microstructural features and provides a link between microscopic and macroscopic. In a mesoscopic model, the length scale is determined by the system; often this scale is similar to the grain size. Microstructural features like grain boundaries or dislocations are considered explicitly. The time scale in a mesoscopic model is determined by the ablation process (such as the pulse length:) rather than the short time limitations of molecular dynamics, yet the highly nonequilibrium behavior is adequately represented. Mesoscopic models are especially important when key process rates vary on a short length scale. Some microstructural feature (like those in dentine or dental enamel) may absorb light much more than others; other features (like grain boundaries) may capture carriers readily, or allow easier evaporation, or capture and retain charge (like grain boundaries); it is these processes which need a mesoscopic analysis. The results described will be taken largely from the work on MgO of Ribeiro, Ramos, and Stoneham for ablation by sub-band Sap light. |
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The mesoscopic modeling of laser ablationGap single-crystalsSemiconductor surfacesRadiationMgODefectsScience & TechnologyIt is common to look at the atomic processes of removal of atoms or ions from surfaces. At this microscopic scale, one has to understand which surface ions are involved, which excited states are created, how electrons are transferred and scattered, and how the excitation leads to ion removal. It is even more common to look at continuum models of energy deposition in solids, and at the subsequent heat transfer In these macroscopic analyses, thermal conduction is combined with empirical assumptions about surface binding. Both these pictures are useful, and both pictures have weaknesses. The atomistic pictures concentrate on relatively few atoms, and do not recognize structural features or the energy and carrier fluxes on larger scales. The continuum macroscopic models leave out crystallographic information and the interplay of the processes with high nonequilibrium at smaller scales. Fortunately, there is a middle way: mesoscopic modeling, which both models the key microstructural features and provides a link between microscopic and macroscopic. In a mesoscopic model, the length scale is determined by the system; often this scale is similar to the grain size. Microstructural features like grain boundaries or dislocations are considered explicitly. The time scale in a mesoscopic model is determined by the ablation process (such as the pulse length:) rather than the short time limitations of molecular dynamics, yet the highly nonequilibrium behavior is adequately represented. Mesoscopic models are especially important when key process rates vary on a short length scale. Some microstructural feature (like those in dentine or dental enamel) may absorb light much more than others; other features (like grain boundaries) may capture carriers readily, or allow easier evaporation, or capture and retain charge (like grain boundaries); it is these processes which need a mesoscopic analysis. The results described will be taken largely from the work on MgO of Ribeiro, Ramos, and Stoneham for ablation by sub-band Sap light.Fundação para a Ciência e a Tecnologia (FCT) – PBICT/FIS/2151/95.Engineering and Physical Sciences Research Council (EPSRC) - GR/L02678, GR/L70615.Springer VerlagUniversidade do MinhoStoneham, A. M.Ramos, Marta M. D.Ribeiro, R. M.1999-121999-12-01T00:00:00Zinfo:eu-repo/semantics/publishedVersioninfo:eu-repo/semantics/articleapplication/pdfhttp://hdl.handle.net/1822/3530eng"Applied Physics A : Materials Science & Processing". ISSN 0947-8396. 69:Suppl.1 (1999) 81-86.0947-839610.1007/s003399900249http://www.springerlink.com/(spxry155h4vowd20rrwug555)/app/home/main.asp?referrer=defaultinfo:eu-repo/semantics/openAccessreponame:Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos)instname:Agência para a Sociedade do Conhecimento (UMIC) - FCT - Sociedade da Informaçãoinstacron:RCAAP2023-07-21T12:05:50Zoai:repositorium.sdum.uminho.pt:1822/3530Portal AgregadorONGhttps://www.rcaap.pt/oai/openaireopendoar:71602024-03-19T18:56:23.840473Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos) - Agência para a Sociedade do Conhecimento (UMIC) - FCT - Sociedade da Informaçãofalse |
dc.title.none.fl_str_mv |
The mesoscopic modeling of laser ablation |
title |
The mesoscopic modeling of laser ablation |
spellingShingle |
The mesoscopic modeling of laser ablation Stoneham, A. M. Gap single-crystals Semiconductor surfaces Radiation MgO Defects Science & Technology |
title_short |
The mesoscopic modeling of laser ablation |
title_full |
The mesoscopic modeling of laser ablation |
title_fullStr |
The mesoscopic modeling of laser ablation |
title_full_unstemmed |
The mesoscopic modeling of laser ablation |
title_sort |
The mesoscopic modeling of laser ablation |
author |
Stoneham, A. M. |
author_facet |
Stoneham, A. M. Ramos, Marta M. D. Ribeiro, R. M. |
author_role |
author |
author2 |
Ramos, Marta M. D. Ribeiro, R. M. |
author2_role |
author author |
dc.contributor.none.fl_str_mv |
Universidade do Minho |
dc.contributor.author.fl_str_mv |
Stoneham, A. M. Ramos, Marta M. D. Ribeiro, R. M. |
dc.subject.por.fl_str_mv |
Gap single-crystals Semiconductor surfaces Radiation MgO Defects Science & Technology |
topic |
Gap single-crystals Semiconductor surfaces Radiation MgO Defects Science & Technology |
description |
It is common to look at the atomic processes of removal of atoms or ions from surfaces. At this microscopic scale, one has to understand which surface ions are involved, which excited states are created, how electrons are transferred and scattered, and how the excitation leads to ion removal. It is even more common to look at continuum models of energy deposition in solids, and at the subsequent heat transfer In these macroscopic analyses, thermal conduction is combined with empirical assumptions about surface binding. Both these pictures are useful, and both pictures have weaknesses. The atomistic pictures concentrate on relatively few atoms, and do not recognize structural features or the energy and carrier fluxes on larger scales. The continuum macroscopic models leave out crystallographic information and the interplay of the processes with high nonequilibrium at smaller scales. Fortunately, there is a middle way: mesoscopic modeling, which both models the key microstructural features and provides a link between microscopic and macroscopic. In a mesoscopic model, the length scale is determined by the system; often this scale is similar to the grain size. Microstructural features like grain boundaries or dislocations are considered explicitly. The time scale in a mesoscopic model is determined by the ablation process (such as the pulse length:) rather than the short time limitations of molecular dynamics, yet the highly nonequilibrium behavior is adequately represented. Mesoscopic models are especially important when key process rates vary on a short length scale. Some microstructural feature (like those in dentine or dental enamel) may absorb light much more than others; other features (like grain boundaries) may capture carriers readily, or allow easier evaporation, or capture and retain charge (like grain boundaries); it is these processes which need a mesoscopic analysis. The results described will be taken largely from the work on MgO of Ribeiro, Ramos, and Stoneham for ablation by sub-band Sap light. |
publishDate |
1999 |
dc.date.none.fl_str_mv |
1999-12 1999-12-01T00:00:00Z |
dc.type.status.fl_str_mv |
info:eu-repo/semantics/publishedVersion |
dc.type.driver.fl_str_mv |
info:eu-repo/semantics/article |
format |
article |
status_str |
publishedVersion |
dc.identifier.uri.fl_str_mv |
http://hdl.handle.net/1822/3530 |
url |
http://hdl.handle.net/1822/3530 |
dc.language.iso.fl_str_mv |
eng |
language |
eng |
dc.relation.none.fl_str_mv |
"Applied Physics A : Materials Science & Processing". ISSN 0947-8396. 69:Suppl.1 (1999) 81-86. 0947-8396 10.1007/s003399900249 http://www.springerlink.com/(spxry155h4vowd20rrwug555)/app/home/main.asp?referrer=default |
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info:eu-repo/semantics/openAccess |
eu_rights_str_mv |
openAccess |
dc.format.none.fl_str_mv |
application/pdf |
dc.publisher.none.fl_str_mv |
Springer Verlag |
publisher.none.fl_str_mv |
Springer Verlag |
dc.source.none.fl_str_mv |
reponame:Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos) instname:Agência para a Sociedade do Conhecimento (UMIC) - FCT - Sociedade da Informação instacron:RCAAP |
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Agência para a Sociedade do Conhecimento (UMIC) - FCT - Sociedade da Informação |
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RCAAP |
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Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos) |
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Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos) |
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Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos) - Agência para a Sociedade do Conhecimento (UMIC) - FCT - Sociedade da Informação |
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