• JoomlaWorks Simple Image Rotator
  • JoomlaWorks Simple Image Rotator
  • JoomlaWorks Simple Image Rotator
  • JoomlaWorks Simple Image Rotator
  • JoomlaWorks Simple Image Rotator
  • JoomlaWorks Simple Image Rotator
  • JoomlaWorks Simple Image Rotator
  • JoomlaWorks Simple Image Rotator
  • JoomlaWorks Simple Image Rotator
  • JoomlaWorks Simple Image Rotator
 
  Bookmark and Share
 
 
Doctoral Thesis
DOI
10.11606/T.54.1989.tde-10032015-110018
Document
Author
Full name
Giomal Aparecido Antonio
Institute/School/College
Knowledge Area
Date of Defense
Published
São Carlos, 1989
Supervisor
Committee
Hipolito, Oscar (President)
Aegerter, Michel Andre
Continentino, Mucio Amado
Koberle, Roland
Santos, Paulo Ventura
Title in Portuguese
Dinâmica molecular aplicada à agregados e vidros calcogenetos
Keywords in Portuguese
Não disponível
Abstract in Portuguese
Neste trabalho, nós aplicamos a técnica de Dinâmica Molecular usando um potencial de interação entre três corpos na investigação da estabilidade e energética de micro-agregados de Ge. Os resultados estão em bom acordo com o experimento de fotofragmentação, no qual os números mágicos 6 e 10 foram encontrados como os fragmentos mais estáveis. Nos também estudamos o vidro calcogeneto SiSe2, através da mesma técnica. Correlações estruturais na faixa de ordem de curto alcance até alcance intermediário são investigadas. O fator de estrutura estático total calculado está em excelente acordo com os resultados obtidos por difração e espalhamento de nêutrons. As fases amorfas consistem de tetraedros Si(Se4)1/2 ligeiramente distorcidos, 53% dos quais são conectados aos demais pelas arestas e o restante divide vértices. Uma pequena fração (≈ 5%) dos tetraedros que dividem arestas são as entidades formadoras de fragmentos tipo cadeia unidimensional, que se estende até um máximo de 10Å. A partir da estatística de anéis e de fragmentos, nós encontramos que estes fragmentos tipo cadeia unidimensional ocorrem predominantemente em anéis de ordem maior que 8
Title in English
Not available
Keywords in English
Not available
Abstract in English
We applied the molecule dynamics (MD) technique using a three-body interaction potential in order to investigate the stability and energetics of Ge micro-clusters. The results are in good agreement with the photo-fragmentation experiment, in which the magic numbers 6 and 10 were found as the most stable fragments. We also studied the chalcogenide glass SiSe2, through the same technique. Structural correlations ranging from short to medium-range order were investigated. The calculated static structure factor is in excellent agreement with neutron measurements. The amorphous states consist of distorted Si(Se4)1/2 tetrahedral, 53% of which are edge-sharing (E-S) and the remaining share corners. A small fraction (≈ 5%) of the E-S tetrahedral are the building blocks of chain-like fragments that extended up to 10Å. From the statistics of rings and fragments, we found that chain-like fragments occur predominantly in 9-fold or larger rings
 
WARNING - Viewing this document is conditioned on your acceptance of the following terms of use:
This document is only for private use for research and teaching activities. Reproduction for commercial use is forbidden. This rights cover the whole data about this document as well as its contents. Any uses or copies of this document in whole or in part must include the author's name.
GiomalAntonioD.pdf (4.94 Mbytes)
Publishing Date
2015-03-16
 
WARNING: Learn what derived works are clicking here.
All rights of the thesis/dissertation are from the authors
Centro de Informática de São Carlos
Digital Library of Theses and Dissertations of USP. Copyright © 2001-2019. All rights reserved.