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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Filmes nanom?tricos de FeN e ALN crescidos por sputtering e aplica??es do efeito peltier

Moura, Jos? Am?rico de Sousa 17 December 2010 (has links)
Made available in DSpace on 2014-12-17T15:14:52Z (GMT). No. of bitstreams: 1 JoseASM_TESE.pdf: 5255189 bytes, checksum: cf0724bd476902a8aa17f19022619211 (MD5) Previous issue date: 2010-12-17 / Conselho Nacional de Desenvolvimento Cient?fico e Tecnol?gico / This study will show the capability of the reactive/nonreactive sputtering (dc/rf) technique at low power for the growth of nanometric thin films from magnetic materials (FeN) and widegap semiconductors (AlN), as well as the technological application of the Peltier effect using commercial modules of bismuth telluride (Bi2Te3). Of great technological interest to the high-density magnetic recording industry, the FeN system represents one of the most important magnetic achievements; however, diversity of the phases formed makes it difficult to control its magnetic properties during production of devices. We investigated the variation in these properties using ferromagnetic resonance, MOKE and atomic force microscopy (AFM), as a function of nitrogen concentration in the reactive gas mixture. Aluminum nitride, a component of widegap semiconductors and of considerable interest to the electronic and optoelectronic industry, was grown on nanometric thin film for the first time, with good structural quality by non-reactive rf sputtering of a pure AlN target at low power (≈ 50W). Another finding in this study is that a long deposition time for this material may lead to film contamination by materials adsorbed into deposition chamber walls. Energy-dispersive X-ray (EDX) analysis shows that the presence of magnetic contaminants from previous depositions results in grown AlN semiconductor films exhibiting magnetoresistance with high resistivity. The Peltier effect applied to commercially available compact refrigeration cells, which are efficient for cooling small volumes, was used to manufacture a technologically innovative refrigerated mini wine cooler, for which a patent was duly registered / Neste trabalho ser? mostrado a habilidade da t?cnica de sputtering (dc/rf) reativo/n?o-reativo a baixa pot?ncia para o crescimento de filmes nanom?tricos de materiais magn?ticos (FeN) e semicondutores de gap largo (AlN) assim como a aplica??o tecnol?gica do efeito peltier por m?dulos comerciais de Telureto de Bismuto (Bi2Te3). De grande interesse tecnol?gico para ind?stria de grava??o magn?tica de altas densidades o sistema FeN apresenta um dos mais altos momentos magn?ticos, entretanto a diversidade de fases formadas torna-o ainda, de dif?cil controle as suas propriedades magn?ticas para produ??o de dispositivos. Neste trabalho foi investigado a varia??o destas propriedades por resson?ncia ferromagn?tica, MOKE e microscopia de for?a at?mica (AFM) em fun??o da concentra??o de nitrog?nio na mistura gasosa do crescimento reativo. O Nitreto de Alum?nio, enquadrado nos semicondutores de gap largo e de grande interesse na ind?stria eletr?nica e optoeletr?nica foi crescido em filmes nanom?tricos, de modo in?dito, com boa qualidade estrutural a partir de alvo puro de AlN por sputtering rf n?o-reativo a baixa pot?ncia (~50W). Outra verifica??o deste trabalho ? que o longo tempo de deposi??o para este material, pode levar a contamina??o dos filmes por materiais adsorvidos nas paredes da c?mara de deposi??o. A investiga??o por EDX mostra a presen?a de contaminantes magn?ticos, provenientes de deposi??es anteriores, leva os filmes semicondutores de AlN crescidos a apresentarem magnetoresist?ncia com resistividade alta. O efeito peltier aplicado nas c?lulas compactas de refrigera??o dispon?veis comercialmente e eficientes para resfriamento de pequenos volumes foi aplicada na cria??o de uma adega refrigerada disponibilizado para a ind?stria local como inova??o tecnol?gica com registro de patente

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