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Previous issue date: 2010-03-23 === The purpose of this study is to describe the implementation of the Low Energy Electron Diffaction (LEED) technique in the Laboratory of Magnetic Nanostructures and Semiconductors of the Department of Theoretical and Experimental Physics of the Universidade Federal do Rio Grande do Norte (UFRN), Natal, Brazil. During this work experimental apparatus were implemented for a complete LEED set-up. A new vacuum system was also set up. This was composed of a mechanical pump, turbomolecular pump and ionic pump for ultra-high vacuum and their respective pressure measurement sensors (Pirani gauge for low vacuum measures and the wide range gauge -WRG); ion cannon maintenance, which is basically mini-sputtering, whose function is sample cleaning; and set-up, maintenance and handling of the quadrupole mass spectrometer, whose main purpose is to investigate gas contamination inside the ultra-high vacuum chamber. It should be pointed out that the main contribution of this Master's thesis was the set-up of the sample heating system; that is, a new sample holder. In addition to the function of sample holder and heater, it was necessary to implement the function of sustaining the ultra-high vacuum environment. This set of actions is essential for the complete functioning of the LEED technique === O objetivo deste trabalho ? descrever a implementa??o da t?cnica de Difra??o de el?trons de Baixa Energia (Low Energy Electron Diffaction - LEED) no Laborat?rio de Nanoestruturas Magn?ticas e Semicondutoras do Departamento de F?sica Te?rica e Experimental da UFRN. Ao longo deste trabalho, foram realizadas implementa??es de aparatos experimentais para a completa montagem do LEED. Um novo sistema de v?cuo foi montado, este ? composto pela bomba mec?nica, bomba turbomolecular e bomba i?nica para ultra alto v?cuo e seus respectivos sensores de medidas de press?o (medidor Pirani, para medidas de baixo v?cuo e o medidor de alcance amplo WRG); manuten??o do canh?o de ions, que ? basicamente um mini-sputtering, com fun??o de limpeza das amostras; montagem, manuten??o e manuseio do espectr?metro de massa por quadrupolo, cuja finalidade principal ? investigar a contamina??o gasosa no interior da c?mara de ultra alto v?cuo. Destaque-se, que a principal contribui??o deste trabalho foi a montagem do sistema de aquecimento da amostra, ou seja, um novo porta-amostra. Neste al?m da fun??o de porta-amostra e aquecedor, foi necess?rio implementar a fun??o de sustenta??o no ambiente de ultra-alto v?cuo. Esse conjunto de a??es ? fundamental para o funcionamento completo da t?cnica LEED
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