Condensed Matter Physics
Mostrando 25-36 de 41 artigos, teses e dissertações.
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25. ProduÃÃo e caracterizaÃÃo estrutural, microestrutural e magnÃtica de Perovskitas complexas do tipo Ba2La1-xTRxZrOy com TR=Sr, Fe
Este trabalho apresenta a produÃÃo e caracterizaÃÃo das perovskitas duplas Ba2LaZrO5:5 , jà reportada anteriormente, Ba2FeZrO5:5 e Ba2La1-xSrxZrO5:5+ estas Ãltimas produzidas pela primeira vez atà o nosso conhecimento. As duas primeiras foram produzidas utilizando o mÃtodo de combustÃo, e caracterizadas morfologicamente por microscopia eletrÃnica
Publicado em: 2006
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26. Estudo estrutural e eletro-óptico da fase B2 de materiais com moléculas de banana / Structural and electro-optical studies of the B2 phase of materials with banana molecules
Com base em resultados de DSC, análise estrutural por difração de raios X e observações de textura, analisamos os efeitos da mistura do solvente apolar hexadecano com cristais líquidos formados pelas moléculas banana 1,3-fenilenobis[4-(4-tetradecilfeniliminometil)benzoato] (MB14) e 4-cloro-1,3-fenilenobis[4-(4-tetradecilfeniliminometil) benzoato] (MB1
Publicado em: 2006
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27. ProduÃÃo de heterojunÃÃes de polianilina/silÃcio e nanofibras de polianilina para aplicaÃÃes em dispositivos hÃbridos
In this work we develop the methodology for the synthesis and fabrication of Polyaniline (PANI) â Silicon (Si) heterojunctions, with great potential for technological applications as sensors in different areas such as optics, ionizing radiation and gas detection. Besides, we were able to implement the electrospinnin technique with the goal of producing poly
Publicado em: 2006
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28. Análise dos efeitos da temperatura nos acoplamentos de modelos escalares O(N) x O(N)
The aim of this work is to analyse how the counter intuitive phenomena known as Symmetry Non Restoration and Inverse Symmetry Breaking manifest themselves within multi scalar field theories displaying O(N)O(N) symmetry. Both, the relativistic as well as the non relativistic versions of such models are investigated here. For the relativistic case, which is im
Publicado em: 2005
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29. Non gravitational black holes
Analogue models of general relativity have recently been considered with great interest by the scientific community. They connect branches of physics as different as gravitation, condensed matter physics, electrodynamics, acoustics, and quantum field theory. One of the main expectations about such models lies on the possibility of testing in laboratory some
Brazilian Journal of Physics. Publicado em: 2004-12
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30. Percolation of Monte Carlo clusters
Percolation theory is of interest in problems of phase transitions in condensed matter physics, and in biology and chemistry. More recently, concepts of percolation theory have been invoked in studies of color deconfinement at high temperatures in Quantum Chromodynamics. In the present paper we briefly review the basic concept of percolation theory, exemplif
Brazilian Journal of Physics. Publicado em: 2004-03
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31. Propriedades estruturais, eletrônicas e termodinâmicas dos nitretos do grupo-III e de suas ligas / Structural, electronic and thermodynamic properties of group-III nitrides and their alloys.
Neste trabalho foram efetuados estudos importantes e pioneiros sobre as propriedades estruturais, eletrônicas e termodinâmicas dos nitretos e de suas ligas, através de dois métodos de primeiros princípios distintos, o FLAPW (\"Full-potential Linear Augmented Plane Wave\") e o pseudopotencial combinado com a aproximação quasequímica generalizada. Na p
IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia. Publicado em: 10/05/2001
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32. Physics in the Global Monopole Spacetime
In this paper we review some important aspects of the global monopole spacetime and present how this manifold modifies, at classical and quantum points of view, the movement of a charged particle. The explicit calculations of the renormalized vacuum expectation values of the energy-momentum tensors, áTmn(x)<
Brazilian Journal of Physics. Publicado em: 2001-06
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33. Field theory and condensed matter: account of a successful interaction
We present a review of some applications of quantum field theory in the physics of condensed matter stressing the extremely fruitful interaction between these two areas. The examples considered include the Kondo effect, Polymers, High-Tc superconductivity and Spin Glasses.
Brazilian Journal of Physics. Publicado em: 2000-06
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34. Condensed Matter Physics as a laboratory for gravitation and Cosmology
The geometric language of General Relativity is not normally related to Condensed Matter (CM) Physics since it is the electromagnetic and not the gravitational interaction that dominates the physics of CM systems. What points in common would then CMP have with Cosmology and the dynamics of objects in a gravitational field? There is at least one that is very
Brazilian Journal of Physics. Publicado em: 2000-06
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35. Viruses and the physics of soft condensed matter
National Academy of Sciences.
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36. Toward room temperature superconductivity?
The last 12 months have witnessed frenzied activity in condensed matter physics, unmatched by any other since the invention of the laser. In this article, we summarize the status, promise, and problems in the field of high-temperature superconductivity. We also comment on the mechanisms and policies needed for the United States to economically benefit from t