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Previous issue date: 2014-10-31 / CAPES / Understanding the structural properties of dislocations is essential since these defects govern the processes plastic deformation of materials. Particularly in semiconductors, these studies are important given the relevance of these materials for microelectronics. In this work, our focus will be the 90o partial dislocations in silicon. For the theoretical study of atomic-scale crystal dislocations, we use simulations based on semi-empirical quantum-mechanical methods closely linked to the tight-binding treatment, since it considers in its formulation that crystalline electronic states can be described in terms of atomic orbitals: Density Matrix Method Tight-Binding Order-N (DMTB). This method has a low computational cost which allows us to work with very large systems atoms in structures representation -including thousands of sites. In short, we describe how to produce and represent the 90o partial dislocations in Si, we consider three models for its core structure: a unreconstructed where the atoms have an almost fivefold coordination; a model reconstructed with period equal to the perfect lattice; and a model with twice period comparing with the perfect lattice. Finally, we calculate the range in energy of the system with the distance between the dislocations and the free surface of Si. / Compreender as propriedades estruturais de discord?ncias cristalinas ? fundamental uma vez que estes defeitos governam os processos de deforma??o pl?stica em materiais. Particularmente em semicondutores, esses estudos s?o importantes dada a relev?ncia desses materiais para a microeletr?nica. Neste trabalho nosso foco ser?o as discord?ncias cristalinas parciais a 90o em sil?cio. Para o estudo te?rico em escala at?mica das discord?ncias cristalinas, usamos simula??es baseadas em metodologias quanto-mec?nicas semi-emp?ricas atrav?s de um m?todo intimamente ligado ao tratamento tight-binding, uma vez que considera em sua formula??o que os estados eletr?nicos cristalinos podem ser descritos em termos de orbitais at?micos: M?todo da Matriz Densidade Tight-Binding de Ordem-N (DMTB). Este m?todo tem um custo computacional baixo o que permite que trabalhemos com sistemas muito grandes de ?tomos na representa??o das estruturas ? com milhares de s?tios inclusive. Em suma, descrevemos como produzir e representar as discord?ncias parciais a 90o em Si consideramos tr?s modelos para sua estrutura de caro?o: um n?o reconstru?do onde os ?tomos possuem uma coordena??o quase qu?ntupla; um modelo reconstru?do com per?odo igual ao per?odo da rede perfeita; e um modelo com per?odo dobrado em rela??o ao da rede perfeita. Por fim, calculamos a varia??o da energia do sistema com a dist?ncia entre as discord?ncias e a superf?cie livre do Si.
| Identifer | oai:union.ndltd.org:IBICT/oai:localhost:jspui/2091 |
| Date | 31 October 2014 |
| Creators | OLIVEIRA, Arnaldo Cesar Almeida |
| Contributors | Ara?jo, Mois?s Monteiro de, Oliveira, Clarissa de, Ara?jo, Mois?s Monteiro de, Bauerfeldt, Glauco Favilla, Silva, Alexandre Pinheiro da |
| Publisher | Universidade Federal Rural do Rio de Janeiro, Programa de P?s-Gradua??o em Modelagem Matem?tica e Computacional, UFRRJ, Brasil, Instituto de Ci?ncias Exatas |
| Source Sets | IBICT Brazilian ETDs |
| Language | Portuguese |
| Detected Language | English |
| Type | info:eu-repo/semantics/publishedVersion, info:eu-repo/semantics/masterThesis |
| Format | application/pdf |
| Source | reponame:Biblioteca Digital de Teses e Dissertações da UFRRJ, instname:Universidade Federal Rural do Rio de Janeiro, instacron:UFRRJ |
| Rights | info:eu-repo/semantics/openAccess |
| Relation | ALEXANDER, H. Dislocations in Solids. Amsterdam: Elsevier Science Publishers, 1986. Citado 2 vezes nas p?ginas 52 e 53. ARA?JO, M. M. Estudos Te?ricos Sobre Discord?ncias Cristalinas em Sil?cio. [S.l.]: Tese de Doutorado apresentada ? UFMG, 2006. Citado na p?gina 25. ASCHROFT, N. W. Solid State Physics. 3. ed. [S.l.]: Sauders College Publishing, 1976. Citado 2 vezes nas p?ginas 29 e 39. ATKINS, P.; FRIEDMAN, R. Molecular Quantum Mechanics. Oxford: Oxford University Press, 1997. Citado 2 vezes nas p?ginas 36 e 37. BALL, D. W. Physical Chemestry. [S.l.]: Brooks/Cole, 2003. Citado na p?gina 31. BATSON, P. E. Atomic and electronic structure of a dissociated 60o misfit dislocation in gexsi(1-x). Phys. Rev. Lett., American Physical Society, v. 83, p. 4409?4412, Nov 1999. Dispon?vel em: <http://link.aps.org/doi/10.1103/PhysRevLett.83.4409>. Citado na p?gina 57. BENNETTO, J.; NUNES, R. W.; VANDERBILT, D. Period-doubled structure for the 90o partial dislocation in silicon. Phys. Rev. Lett., American Physical Society, v. 79, p. 245?248, Jul 1997. Dispon?vel em: <http://link.aps.org/doi/10.1103/PhysRevLett.79.245>. Citado 2 vezes nas p?ginas 54 e 57. BIGGER, J. R. K. et al. Atomic and electronic structures of the 90o partial dislocation in silicon. Phys. Rev. Lett., American Physical Society, v. 69, p. 2224?2227, Oct 1992. Dispon?vel em: <http://link.aps.org/doi/10.1103/PhysRevLett.69.2224>. Citado na p?gina 53. BLASE, X. et al. Structure and energy of the 90o partial dislocation in diamond: A combined ab initio and elasticity theory analysis. Phys. Rev. Lett., American Physical Society, v. 84, p. 5780?5783, Jun 2000. Dispon?vel em: <http://link.aps.org/doi/10.1103/ PhysRevLett.84.5780>. Citado na p?gina 54. BULATOV, V. V. et al. Kink asymmetry and multiplicity in dislocation cores. Phys. Rev. Lett., American Physical Society, v. 79, p. 5042?5045, Dec 1997. Dispon?vel em: <http://link.aps.org/doi/10.1103/PhysRevLett.79.5042>. Citado na p?gina 53. DUESBERY M. S.AND RICHARDDSON, G. Y. [S.l.]: Crit. Rev. Solid State Mater. Sci, 1991. Citado na p?gina 57. FEYNMAN, R. P. Forces in molecules. Phys. Rev., American Physical Society, v. 56, p. 340?343, Aug 1939. Dispon?vel em: <http://link.aps.org/doi/10.1103/PhysRev.56.340>. Citado na p?gina 44. HARRISON, W. A. Eletronic Structure and the Properties of Solids. San Francisco: W. H. Freeman and Company, 1980. Citado na p?gina 36. HIRSCH, P. B. [S.l.]: Mater. Sci. Technol, 1985. Citado na p?gina 57. HIRTH, J. P.; LOTHE, J. Theory of Dislocation. New York: John Wiley & Sons, Inc, 1982. Citado na p?gina 28. JONES, R.; ?BERG, S. Oxygen frustration and the interstitial carbon-oxygen complex in si. Phys. Rev. Lett., American Physical Society, v. 68, p. 86?89, Jan 1992. Dispon?vel em: <http://link.aps.org/doi/10.1103/PhysRevLett.68.86>. Citado na p?gina 52. KITTEL, C. Introdution to Solid State Physics. New York: John Wiley & Sons CO, 1996. Citado na p?gina 17. KOLAR, H. R.; SPENCE, J. C. H.; ALEXANDER, H. Observation of moving dislocation kinks and unpinning. Phys. Rev. Lett., American Physical Society, v. 77, p. 4031?4034, Nov 1996. Dispon?vel em: <http://link.aps.org/doi/10.1103/PhysRevLett.77.4031>. Citado 2 vezes nas p?ginas 54 e 57. LI, X.-P.; NUNES, R. W.; VANDERBILT, D. Density-matrix electronic-structure method with linear system-size scaling. Phys. Rev. B, American Physical Society, v. 47, p. 10891?10894, Apr 1993. Dispon?vel em: <http://link.aps.org/doi/10.1103/PhysRevB.47. 10891>. Citado na p?gina 38. MCWEENY, R. Some recent advances in density matrix theory. Rev. Mod. Phys., American Physical Society, v. 32, p. 335?369, Apr 1960. Dispon?vel em: <http://link.aps.org/doi/10.1103/RevModPhys.32.335>. Citado na p?gina 41. NUNES, R. W.; BENNETTO, J.; VANDERBILT, D. Structure, barriers, and relaxation mechanisms of kinks in the 90o partial dislocation in silicon. Phys. Rev. Lett., American Physical Society, v. 77, p. 1516?1519, Aug 1996. Dispon?vel em: <http://link.aps.org/doi/10.1103/PhysRevLett.77.1516>. Citado na p?gina 53. NUNES, R. W.; BENNETTO, J.; VANDERBILT, D. Atomic structure of dislocation kinks in silicon. Phys. Rev. B, American Physical Society, v. 57, p. 10388?10397, May 1998. Dispon?vel em: <http://link.aps.org/doi/10.1103/PhysRevB.57.10388>. Citado na p?gina 54. NUNES, R. W.; BENNETTO, J.; VANDERBILT, D. Core reconstruction of the 90o partial dislocation in nonpolar semiconductors. Phys. Rev. B, American Physical Society, v. 58, p. 12563?12566, Nov 1998. Dispon?vel em: <http: //link.aps.org/doi/10.1103/PhysRevB.58.12563>. Citado na p?gina 54. ?BERG, S. et al. First-principles calculations of the energy barrier to dislocation motion in si and gaas. Phys. Rev. B, American Physical Society, v. 51, p. 13138?13145, May 1995. Dispon?vel em: <http://link.aps.org/doi/10.1103/PhysRevB.51.13138>. Citado na p?gina 54. PADILHA, A. F. Materiais de Engenharia. 1. ed. [S.l.]: Hemus livraria, Distribuidora e Editora S.A., 2000. Citado 3 vezes nas p?ginas 22, 23 e 24. SAITO, R.; DRESSELHAUS, G.; DRESSELHAUS, M. S. Physical Properties of Carbon Nanotubes. Imperial College Press: Imperial College Press, 1998. Citado na p?gina 36. SUZUKI, T.; TAKUCHI, S.; YOSHINAGA, H. Dislocation Dynamics and Pasticity. 1. ed. New York: Spring Verlag, 1989. Citado na p?gina 53. TINKHAM, M. Group Theory an Quantum Mechanics. San Francisco: McGraw-Hill, 1964. Citado 2 vezes nas p?ginas 36 e 37. |
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