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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES Zirconium nitride (ZrN) and ternary Zr1-XSiXN thin films were deposited by reactive magnetron sputtering (RMS) with substrate heating at different temperatures in order to study the influence of the deposition temperature on the composition, mechanical and tribological properties and oxidation resistance. The ternary systems were produced with 1.6 at.% and 8.0 at.% of Si, as determined by Rutherford backscattering spectroscopy analysis (RBS). The depositions were carried out without external substrate heating (SA), at 300 °C, 500 °C and 700 °C. Characterizations of X-ray diffraction with grazing incidence X-ray diffraction (GIXRD), conventional scanning electron with field emission gun (SEM-FEG), nanoindentation tests, ball-on-flat linearly reciprocating sliding wear, scratch test and oxidation tests were used to detect possible changes in the structures and properties of the films. The results found were compared with the literature and showed that the increase in the deposition temperature promoted significant gains in the properties presented by the coatings, especially for those with the addition of 8 at.% Si. For this Si content, the process of recrystallization of the material was also observed when deposited with substrate heating, in comparison with the SA depositions that vi showed amorphous behavior. Indicative that there was an increase in the Si solubility limit in the ZrN matrix from the formation of a supersaturated solid solution in Si. In addition, it was possible to observe a greater resistance to oxidation for those coatings deposited at high temperatures. Filmes finos de nitreto de zircônio puro (ZrN) e com adição de diferentes teores de silício (Zr1-XSiXN) foram depositados por magnetron sputtering reativo (RMS) em diferentes temperaturas a fim de estudar a influência da temperatura de deposição na composição do filme, nas propriedades mecânicas e tribológicas e na resistência a oxidação dos revestimentos. Para formação do sistema ternário Zr-Si-N foram utilizados os teores de 1,6 e 8,0 at.% de Si, determinados por análise de espectroscopia de retroespalhamento de Rutherford (RBS). As deposições foram realizadas sem aquecimento externo de substrato (SA), a 300 °C, 500 °C e 700 °C. Caracterizações de difração de raios-X com ângulo de incidência rasante (GIXRD) e microscopia eletrônica de varredura convencional (MEV) e com emissão de campo (MEV-FEG), ensaios de nanodureza, testes tribológicos do tipo esfera-sobre-plano com movimento linear recíproco (ball-on-flat reciprocating), teste de riscamento (scratch test) e ensaios de oxidação foram utilizados para verificação de possíveis mudanças nas estruturas e propriedades dos filmes. Os resultados encontrados foram comparados com a literatura e mostraram que o aumento da temperatura de deposição promoveu ganhos significativos iv nas propriedades apresentadas pelos revestimentos, especialmente para aqueles com adição de 8,0 at.% de Si. Para este teor de Si também foi observado o processo de recristalização do material quando depositado com aquecimento de substrato, em comparação com as deposições SA que apresentou comportamento amorfos. Indicativo de que ocorreu um aumento no limite de solubilidade do Si na matriz do ZrN a partir da formação de uma solução sólida supersaturada em Si. Além disso, foi possível observar uma maior resistência à oxidação para aqueles revestimentos depositados em elevadas temperaturas. São Cristóvão, SE

Cubic boron nitride (c-BN) is a material which exhibits similar properties as diamond. Obviously, it makes c-BN attractive for a broad field of applications like tribological and anti-corrosion coatings or as a starting material for high-temperature and high-power electronic devices. Boron nitride films were prepared by ion beam assisted deposition (IBAD) technique on top of Si(001) substrates. In order to overcome the stress/adhesion-related limitation of c-BN film thicknesses, an approach was taken based on sequential ion-induced stress relaxation and growth of thin layers stacked on top of each other to form a thick film. An appropriate in situ sputter cleaning procedure of a c-BN surface was developed resulting in an immediate c-BN growth on top of such a cleaned substrate without any intermediate layers. According to High Resolution Transmission Electron microscopy measurements, c-BN films are also found to be nanocrystalline (typical crystal size 5nm). A promising alternative way to enhance the crystalline quality and adhesion of c-BN films is significant increase of the deposition temperature up to the order of 1000 °C. It has been found that such 1000 °C-type temperatures do not cause Si diffusion from the substrate into the BN film. Cubic BN and hexagonal (h-) BN were also studied with respect to the depth profiles of incorporated Ar using Rutherford backscattering. Diffusion related changes of the Ar depth profiles for both c-BN and h-BN were only observed for temperatures well above 730 °C. In that case, the Ar mobility is attributed to grain boundary diffusion, which appears to be one order of magnitude higher in h-BN than in c-BN film. Grain boundary diffusion coefficients of Ar in h-BN and in c-BN have been estimated. On the other hand, bulk diffusion seems to be negligible at least in c-BN even at 1100 °C.