• 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.43.1995.tde-28022014-112323
Document
Author
Full name
Maria de Fátima da Silva Verdeaux
Institute/School/College
Knowledge Area
Date of Defense
Published
São Paulo, 1995
Supervisor
Committee
Figueiredo Neto, Antonio Martins (President)
Gama, Sérgio
Mesquita, Oscar Nassif de
Oliveira, Mario Jose de
Rechenberg, Hercilio Rodolfo
Title in Portuguese
Propriedades ópticas e ordem local de ferrofluidos iônicos investigadas por meio de espalhamento de raios X e medidas da birrefringência.
Keywords in Portuguese
Física da matéria condensada
Física do estado sólido
Abstract in Portuguese
Os ferrofluidos iônicos de 'MN''FE IND. 2''O IND. 4', 'gama' - 'FE IND. 2''O IND. 3' e 'CO''FE IND. 2''O IND. 4' foram investigados pelas técnicas de óptica e espalhamento de raios X. Investigamos o comportamento desses ferrofluidos, na presença e na ausência de campo magnético e quando submetidos à variação de temperatura. A birrefringência óptica medida em função da temperatura, sem qualquer campo magnético, mostrou a existência de uma ordem tipo nemática nesses materiais. Os resultados obtidos com as medidas de anisotropia óptica podem ser explicados através da anisotropia de forma dos grãos e o fator clássico de despolarização da luz. Experimentos com a técnica de espalhamento de raios X mostrou a existência de pequenos agregados de grãos nas amostras estudadas.
Title in English
Optical properties and local order of ionic ferrofluids investigated by X-ray scattering and birefringence measurements.
Keywords in English
Condensed matter physics
Physics of the solid state
Abstract in English
Ionic ferrofluids of MnFe2O4, - Fe2Os Fe2Os and CoFe204 have been investigated by means of optical and x-ray- scattering techniques. An investigation on the behavior of such ferrofluids has been made, when in the presence and absence of a magnetic field, and when submitted to the variation of temperature. The optical birefringence measured as a function of temperature, without any magnetic field, showed the existence of a nematic-type order in these maaterials. The results obtained by the measured optical anisostropy could be explained by the shape anisostropy of the grains and the classical light depolarizing factors. X-ray scattering results indicate the existence of small aggregates in the samples studied.
 
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.
Publishing Date
2014-03-12
 
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 © 2001-2020. All rights reserved.