| Ano de defesa: |
2013 |
| Autor(a) principal: |
Prado, Rodolpho Mouta Monte
 |
| Orientador(a): |
PASCHOAL, Carlos William de Araújo |
| Banca de defesa: |
Silva, Eder Nascimento
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| Tipo de documento: |
Dissertação
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| Tipo de acesso: |
Acesso aberto |
| Idioma: |
por |
| Instituição de defesa: |
Universidade Federal do Maranhão
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| Programa de Pós-Graduação: |
PROGRAMA DE PÓS-GRADUAÇÃO EM FÍSICA/CCET
|
| Departamento: |
FISICA
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| País: |
BR
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| Palavras-chave em Português: |
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| Palavras-chave em Inglês: |
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| Área do conhecimento CNPq: |
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| Link de acesso: |
http://tedebc.ufma.br:8080/jspui/handle/tede/744
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| Resumo: |
In this work we investigated the temperature dependence of point defects in Li₃OCl anti-perovskites using static atomistic simulations. The interionic interactions were modeled by pairwise Buckingham-type pairwise potentials, while the shell model was employed to describe the ions, except the lithium ions that was assumed as a spherical rigid ion. The defects were calculated according to the Mott-Littleton approach for several temperatures between 0 and 600 K. The main intrinsic defects investigated were Schottky, pseudo-Schottky LiCl and Li₂O and Frenkel defects. Results show the most likely defect is the LiCl pseudo-Schottky one, which formation enthalpy is 0,98 eV about at 300 K . The calculated lithium vacancies concentration did not reach values above 10ˉ7, indicating that most of vacancies might be generated by aliovalent extrinsic impurities. The calculated vacancy migration energy agrees very well with that obtained experimentally (0,26 eV ) and it shows that the main ionic conductivity mechanism in is due to the lithium vacancies, occurring along the octahedron vertices. |
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