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Submitted by Guilherme Lemeszenski (guilherme@nead.unesp.br) on 2013-08-22T18:48:44Z No. of bitstreams: 1 S0100-40422008000700020.pdf: 255464 bytes, checksum: 49438dcdbb92d68c278ece21240675c7 (MD5) Made available in DSpace on 2013-08-22T18:48:44Z (GMT). No. of bitstreams: 1 S0100-40422008000700020.pdf: 255464 bytes, checksum: 49438dcdbb92d68c278ece21240675c7 (MD5) Previous issue date: 2008-01-01 Made available in DSpace on 2013-09-30T19:38:46Z (GMT). No. of bitstreams: 2 S0100-40422008000700020.pdf: 255464 bytes, checksum: 49438dcdbb92d68c278ece21240675c7 (MD5) S0100-40422008000700020.pdf.txt: 16926 bytes, checksum: be273b36a1916995154dcd2c57679fe2 (MD5) Previous issue date: 2008-01-01 Submitted by Vitor Silverio Rodrigues (vitorsrodrigues@reitoria.unesp.br) on 2014-05-20T14:18:11Z No. of bitstreams: 2 S0100-40422008000700020.pdf: 255464 bytes, checksum: 49438dcdbb92d68c278ece21240675c7 (MD5) S0100-40422008000700020.pdf.txt: 16926 bytes, checksum: be273b36a1916995154dcd2c57679fe2 (MD5) Made available in DSpace on 2014-05-20T14:18:11Z (GMT). No. of bitstreams: 2 S0100-40422008000700020.pdf: 255464 bytes, checksum: 49438dcdbb92d68c278ece21240675c7 (MD5) S0100-40422008000700020.pdf.txt: 16926 bytes, checksum: be273b36a1916995154dcd2c57679fe2 (MD5) Previous issue date: 2008-01-01 Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) This work focuses in optimizing setup for obtaining TiO2 thin films by polymeric precursor route due to its advantages on stoichiometric and morphological control. Precursor stoichiometry, synthesis pH, solids concentration and rotation speed at deposition were optimized evaluating thin films morphology and thickness. Thermogravimetry and RMN were applied for precursor's characterization and AFM, XRD and ellipsometry for thin films evaluation. Results showed successful attainment of homogeneous nanocrystalline anatase TiO2 thin films with outstanding control over morphological characteristics, mean grain size of 17 nm, packing densities between 57 and 75%, estimated surface areas of 90 m²/g and monolayers thickness within 20 and 128 nm. Universidade Federal de São Carlos (UFSCar) Departamento de Química Universidade Estadual Paulista Júlio de Mesquita Filho Instituto de Química de Araraquara Universidade Estadual Paulista Júlio de Mesquita Filho Instituto de Química de Araraquara

Submitted by Guilherme Lemeszenski (guilherme@nead.unesp.br) on 2013-08-22T18:48:42Z No. of bitstreams: 1 S0100-40422008000500004.pdf: 643050 bytes, checksum: 80c3b67e10f8e5d40009178a04e3de5b (MD5) Made available in DSpace on 2013-08-22T18:48:42Z (GMT). No. of bitstreams: 1 S0100-40422008000500004.pdf: 643050 bytes, checksum: 80c3b67e10f8e5d40009178a04e3de5b (MD5) Previous issue date: 2008-01-01 Made available in DSpace on 2013-09-30T19:38:44Z (GMT). No. of bitstreams: 2 S0100-40422008000500004.pdf: 643050 bytes, checksum: 80c3b67e10f8e5d40009178a04e3de5b (MD5) S0100-40422008000500004.pdf.txt: 40194 bytes, checksum: afba5f6ca2d019d9c748120d86a5151c (MD5) Previous issue date: 2008-01-01 Submitted by Vitor Silverio Rodrigues (vitorsrodrigues@reitoria.unesp.br) on 2014-05-20T14:18:14Z No. of bitstreams: 2 S0100-40422008000500004.pdf: 643050 bytes, checksum: 80c3b67e10f8e5d40009178a04e3de5b (MD5) S0100-40422008000500004.pdf.txt: 40194 bytes, checksum: afba5f6ca2d019d9c748120d86a5151c (MD5) Made available in DSpace on 2014-05-20T14:18:14Z (GMT). No. of bitstreams: 2 S0100-40422008000500004.pdf: 643050 bytes, checksum: 80c3b67e10f8e5d40009178a04e3de5b (MD5) S0100-40422008000500004.pdf.txt: 40194 bytes, checksum: afba5f6ca2d019d9c748120d86a5151c (MD5) Previous issue date: 2008-01-01 Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) Pb/Ti, Sn and Mg-based nanocomposite materials were prepared by the high-energy mechanical milling of commercial powders. The surface of these ceramic compounds was strongly influenced by the doping, diameter of the milling spheres and time of the mechanical milling (amorphization process). Such milling leads to the formation of nanocrystalline materials. The mechanical processing parameters of these compounds were investigated through Brunauer, Emmett and Teller isotherms, wide angle X-ray diffraction, transmission electron microscopy and CO2 adsorption. Universidade Federal de Pelotas Departamento de Química Analítica e Inorgânica Centro Federal de Educação Tecnológica do Maranhão Departamento de Departamento Acadêmico de Química Universidade Federal de São Carlos (UFSCar) Departamento de Química Universidade Estadual Paulista Instituto de Química Departamento de Físico-Química Universidade Federal de Santa Catarina Departamento de Química Universidade Estadual Paulista Instituto de Química Departamento de Físico-Química

Atualmente, há muito interesse no desenvolvimento de materiais nanocristalinos e amorfos, que apresentem alta resistência mecânica combinada com boa ductilidade, abrindo grandes perspectivas tecnológicas para o processamento desses materiais. Devido a sua versatilidade, as ligas amorfas têm mostrado ter propriedades que podem ser utilizadas em diversas áreas, como em memórias de computadores, aplicações em vários tipos de transformadores para potência e usos eletrônicos. A técnica para obter as ligas amorfas utilizada nesse trabalho foi a de solidificação rápida a partir do estado líquido, por melt spinning. O processamento das fitas foi efetuado em duas etapas, inicialmente foi realizado a fusão da liga por indução magnética, posteriormente, a liga foi submetida a nova refusão para melhorar a homogeneização e, em seguida, produziu-se a fita metálica amorfa, utilizando uma taxa de resfriamento em torno de 10³°C/s. Durante o processamento, a fita obtida apresentou-se amorfa e com uma espessura em torno de 25µm. Now, there is a lot of interest in the development of nanocrystalline and amorphous materials, that present high mechanical resistance combined with good ductility, opening great technological perspectives for the processing these of materials. Due to its versatility, the amorphous alloys have been showing to have properties that can be used in several areas, as in memory of computers, applications in several types of transformers for potency and electronic uses. The technique used to obtain of amorphous alloys in this work, it went to of rapid solidification starting from the liquid state, for melt spinning. The processing of the ribbons of was made in two stages, initially the coalition of the alloy was accomplished by magnetic induction, later on, the alloy was submitted the new remelting to improve the homogenizationand soon after, the amorphous metallic ribbon was produced, used of the high cooling rate, around 10³°C/s. During the processing, the obtained ribbon came amorphous and with a thickness around 25µm.

The objectives of this work are to supply a basic background on nanostructured materials and also to report about the obtaining of nanoparticles, mainly, tin dioxide nanocrystalline particles (obtained by using the polymeric precursor method) presenting a high stability against particle growth due to the usage of a metastable solid solution. The synthesis and growth of SnO2 nanoribbons by a carbothermal reduction process are also discussed.