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Filmes de óxido de índio dopado com estanho depositados por magnetron sputtering.; Indium-tin oxide thin films deposited by magnetron sputtering.

Damiani, Larissa Rodrigues
Fonte: Biblioteca Digitais de Teses e Dissertações da USP Publicador: Biblioteca Digitais de Teses e Dissertações da USP
Tipo: Dissertação de Mestrado Formato: application/pdf
Publicado em 16/12/2009 PT
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O óxido de índio dopado com estanho é um semicondutor degenerado de alta transparência no espectro visível e alta condutância elétrica. Por suas propriedades, ele é utilizado como eletrodo transparente em diversas aplicações. Algumas destas aplicações exigem que os filmes sejam depositados sobre substratos poliméricos, que degradam em temperaturas acima de 100 °C. Por este motivo, métodos de deposição que utilizam baixas temperaturas são necessários. O objetivo deste trabalho é o desenvolvimento de técnicas de deposição de filmes de óxido de índio dopado com estanho, em baixas temperaturas (< 100 °C), pelo método de magnetron sputtering de rádio fequência. Filmes foram obtidos sobre substratos de silício, vidro e policarbonato, e suas propriedades físicas, elétricas, ópticas, químicas e estruturais foram analisadas por perfilometria, elipsometria, curvas corrente-tensão, prova de quatro pontas, medidas de efeito Hall, difratometria de raios-X e espectrofotometria. Filmes depositados sobre silício e vidro tiveram resistividade elétrica mínima da ordem de 10^-4 Ohm.cm, enquanto a resistividade do filme obtido sobre policarbonato foi da ordem de 10^-3 Ohm.cm. A transmitância óptica média no espectro visível das amostras variou de 66 a 87 %. Do ponto de vista estrutural...

Sensibilização de nanotubos de Tio2 com CdSe pela técnica de RF magnetron sputtering para aplicação em células fotoeletroquímicas

Fernandes, Jesum Alves
Fonte: Universidade Federal do Rio Grande do Sul Publicador: Universidade Federal do Rio Grande do Sul
Tipo: Tese de Doutorado Formato: application/pdf
POR
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Neste trabalho serão apresentados os resultados referentes à síntese e caracterização de materiais híbridos constituídos de nanotubos de TiO2 e clusters de CdSe (Nt-TiO2/CdSe), além de sua aplicação em células fotoeletroquímicas utilizadas na produção de hidrogênio (H2). A primeira etapa do trabalho envolveu a síntese e caracterização dos nanotubos de TiO2. Inicialmente foram encontradas as condições ótimas para síntese e tratamento térmico dos nanotubos. Foi observado que nanotubos de TiO2 apresentam melhor resposta fotoeletroquímica quando obtidos com cerca de 1 μm de comprimento, no entando a temperaturas de tratamento termico estudas neste trabalho não afetaram sifnificativamente seu comportamento fotoeletroquímica. A segunda etapa envolveu a utilização da técnica de RF Magnetron Sputtering para deposição de nanoparticulas e clusters de CdSe sobre os nanotubos. Primeiramente foi realizado um estudo sobre a dependência das propriedades fotoeletroquímicas com a concentração de CdSe sendo a concentração ótima para este sistema de 3,18x1017 at.cm-2 de Cd e Se. Para avaliar o efeito da cristalinidade do TiO2 sobre a resposta fotoeletroquímica do sistema híbrido (Nt-TiO2/CdSe) antes da deposição de CdSe os nanotubos de TiO2 foram submetidos a tratamentos térmicos em diferentes temperaturas. Nesta etapa foi verificado um efeito significativo da temperatura de tratamento térmico dos nanotubos de TiO2 na formação do hibrido...

Otimização do processo de deposição de filmes TiO2:Mn usando RF magnetron sputtering

Pereira, Andre Luis de Jesus
Fonte: Universidade Estadual Paulista (UNESP) Publicador: Universidade Estadual Paulista (UNESP)
Tipo: Tese de Doutorado Formato: 131 f. : il.
ENG
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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES); Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP); Pós-graduação em Ciência e Tecnologia de Materiais - FC; A busca por um melhor entendimento da inter-relação entre os parâmetros envolvidos no processo de crescimento de filmes de dióxido de titânio (Tio2) e as propriedades estruturais, eletrônicas e magnéticas resultantes foi a principal motivação deste trabalho. Para isso, filmes Ti)2 foram crescidos usando a técnica de RF magnetron sputtering em diferentes condições. Um primeiro conjunto de filmes de Ti)2 não dopados foi depositado com fluxo contínuo de O2. Em outro conjunto, utilizou-se sistemáticas interrupções no fluxo de O2 durante a deposição. O último grupo de amostras foi depositado usando fluxo contínuo O2 e dopagem com Mn. Os filmes do primeiro grupo apresentaram morfologia colunar com estrutura majoritariamente anatase e com gap óptico de ~3,3 eV, independente da temperatura dos substratos (450ºC e 600ºC) e da razão Ar/O2 utilizada. A diminuição do fluxo de O2 provocou um aumento da absorção sub-gap que foi associada a um aumento dos defeitos eletrônicos no material. Um tratamento térmico em vácuo a 800ºC...

AlNxOy thin films deposited by DC reactive magnetron sputtering

Borges, Joel; Vaz, F.; Marques, L.
Fonte: Elsevier Publicador: Elsevier
Tipo: Artigo de Revista Científica
Publicado em //2010 ENG
Relevância na Pesquisa
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AlNxOy thin films were produced by DC reactive magnetron sputtering, using an atmosphere of argon and a reactive gas mixture of nitrogen and oxygen, for a wide range of partial pressures of reactive gas. During the deposition, the discharge current was kept constant and the discharge parameters were monitored. The deposition rate, chemical composition, morphology, structure and electrical resistivity of the coatings are strongly correlated with discharge parameters. Varying the reactive gas mixture partial pressure, the film properties change gradually from metallic-like films, for low reactive gas partial pressures, to stoichiometric amorphous Al2O3 insulator films, at high pressures. For intermediate reactive gas pressures, sub-stoichiometric AlN x O y films were obtained, with the electrical resistivity of the films increasing with the non metallic/metallic ratio.; FEDER - Program COMPETE - Programa Operacional Factores de Competitividade; Fundação para a Ciência e a Tecnologia (FCT) - Project PTDC/CTM/69362/2006; PhD grant Nº SFRH/BD/47118/2008

Morphological and electrical evolution of ZnO: Al thin filmsdeposited by RF magnetron sputtering onto glass substrates

Silva,Érica Pereira da; Chaves,Michel; Durrant,Steven Frederick; Lisboa-Filho,Paulo Noronha; Bortoleto,José Roberto Ribeiro
Fonte: ABM, ABC, ABPol Publicador: ABM, ABC, ABPol
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/12/2014 EN
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In this work, the surface and electrical characteristics ZnO:Al thin films deposited by RF magnetron sputtering onto glass substrates have been investigated. Analysis of surface morphologies revealed two growth stages. In the first stage, up to thicknesses of 100 nm, the films show surface structures with a granular form without preferential orientation. Beyond thicknesses of 100 nm, however, the grain structures increase in size and height, producing a pyramidal form and preferred orientation along the c-axis. The XRD results show that the films have a preferred orientation in the (002) plane. Furthermore, with the evolution of the film thickness the electrical resistivity decreases to a minimum of 1.6 × 10- 3 Ω cm for the film of 465 nm thickness. The doping with aluminum atoms produces an increase in concentration of charge carriers to around 8.8 × 10(19) cm- 3. All films exhibit high optical transmittance (above 85%) in the visible region.

Propriedades supercondutoras de filmes finos de Nb depositados por magnetron sputtering

Rolim, Ana Luiza de Souza
Fonte: Universidade Federal de Pernambuco Publicador: Universidade Federal de Pernambuco
Tipo: Outros
PT_BR
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Neste trabalho é estudado a deposição de filmes finos metálicos e refratários por magnetron sputtering utilizando-se tanto de uma fonte de como rf. Os pontos ótimos de trabalho foram determinados em função da pressão na câmara de deposição e da potência das fontes para os seguintes materiais: Nb, Ti, Mo, W e Si, obtendo assim um treinamento na utilização da máquina de deposição ao mesmo tempo que preparando-a para futuros usuários. Especial atenção é dada à deposição e caracterização de filmes finos de Nb com espessura entre 300 Å e 10000 Å. As características supercondutoras destes filmes são analisadas através de medidas de susceptibilidade ac, magnetização dc e da razão de resistência. O diagrama de fase campo magnético temperatura (H-T), obtido de seqüências de esfriamento a campo nulo (ZFC) e em campo (FC), revela uma forte dependência da linha de irreversibilidade com a espessura do filme. Em filmes mais finos a região de irreversibilidade diminui. Este efeito é atribuído a danos superficiais causados por tensões ou por defeitos; Conselho Nacional de Desenvolvimento Científico e Tecnológico

Growth evolution of self-textured ZnO films deposited by magnetron sputtering at low temperatures

Bortoleto, José Roberto Ribeiro; Chaves, Michel; Rosa, Andressa Macedo; Silva, Erica Pereira da; Durrant, Steven Frederick; Trino, Luciana Daniele; Lisboa-Filho, Paulo Noronha
Fonte: Elsevier B.V. Publicador: Elsevier B.V.
Tipo: Artigo de Revista Científica Formato: 210-215
ENG
Relevância na Pesquisa
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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP); Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq); Processo FAPESP: 2008/53311-5; Processo FAPESP: 2011/21345-0; In this work, the evolution of the surface morphology of ZnO thin films deposited by reactive RF magnetron sputtering has been investigated using atomic force microscopy (AFM) and X-ray diffraction (XRD). All AFM images of the films were analyzed using scaling concepts. To study the growth evolution, different ZnO films with thicknesses of up to 1270nm were deposited at temperatures of 100 and 250 degrees C. For the films grown at 100 degrees C, AFM data show that the lateral length xi evolves continuously while the temporal evolution of the root mean square roughness sigma presents two distinct regimes. Early during the depositions, the morphology of the ZnO films is mainly characterized by granular structures. Beyond thickness of about 600nm, pyramid-like structures with {214} crystallographic facets start to develop. For the films grown at 250 degrees C, however, only one growth regime was observed and for the thicker films, the surface morphology consisted of polygonal structures. For the films grown at 100 degrees C, the growth exponents beta...

Morphological and electrical evolution of ZnO:Al thin films deposited by rf magnetron sputtering onto glass substrates

Silva, Erica Pereira da; Chaves, Michel; Durrant, Steven Frederick; Lisboa-Filho, Paulo Noronha; Bortoleto, José Roberto Ribeiro
Fonte: Univ Fed Sao Carlos, Dept Engenharia Materials Publicador: Univ Fed Sao Carlos, Dept Engenharia Materials
Tipo: Artigo de Revista Científica Formato: 1384-1390
ENG
Relevância na Pesquisa
66.94%
Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP); Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq); Processo FAPESP: 2008/53311-5; Processo FAPESP: 2011/21345-0; In this work, the surface and electrical characteristics ZnO:Al thin films deposited by RF magnetron sputtering onto glass substrates have been investigated. Analysis of surface morphologies revealed two growth stages. In the first stage, up to thicknesses of 100 nm, the films show surface structures with a granular form without preferential orientation. Beyond thicknesses of 100 nm, however, the grain structures increase in size and height, producing a pyramidal form and preferred orientation along the c-axis. The XRD results show that the films have a preferred orientation in the (002) plane. Furthermore, with the evolution of the film thickness the electrical resistivity decreases to a minimum of 1.6 x 10(-3) Omega cm for the film of 465 nm thickness. The doping with aluminum atoms produces an increase in concentration of charge carriers to around 8.8 x 10(19) cm(-3). All films exhibit high optical transmittance (above 85%) in the visible region.

Growth of WC-Cr-N and WC-Al-N coatings in a RF-magnetron sputtering process

STANISHEVSKY, Andrei; WALOCK, Michael; ZOU, Yujiao; IMHOFF, Luc; ZAIRI, Amel; NOUVEAU, Corinne
Fonte: Elsevier Publicador: Elsevier
EN_US
Relevância na Pesquisa
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Tungsten carbide-based coatings have been used in a wide variety of industrial applications such as high speed cutting tools, extrusion dies, drills, aerospace industries, and more. A few reports on ternary and quaternary coatings of WC with other elements indicate good prospects for these material systems. The present study focuses on the formation of quaternary WCeCreN and WCeAleN coatings during the simultaneous reactive RF-magnetron sputtering of tungsten carbide and Al or Cr targets in an argon/nitrogen gas mixture. The resulting coatings, with thicknesses of 3.5 mme8.2 mm, were characterized by using several analytical techniques including X-ray diffraction, SEM/EDS, AFM, and X-ray photoelectron spectroscopy. WCeCreN and WCeAleN coatings with high levels of tungsten (i.e. more than 50 at.% of the total metal content) demonstrated dense microstructure. Coatings with lower tungsten content formed columnar grain microstructure, with different surface morphologies depending on the process parameters. It was proposed that crystalline tungsten carbide (with partial N-substitution of C atoms) and chromium (or aluminum) nitride phases coexist in the coatings when the amount of tungsten was greater than 50 at.% of the total metal content; while at lower tungsten content...

Comparative studies on Mo-Cr-N and Al-Cr-N coatings obtained by PVD dual magnetron sputtering

BENLATRECHE, Yacine; NOUVEAU, Corinne; RAHIL, Issan; MARCHAL, Rémy; CHEKOUR, Lounis
Fonte: WILEY Publicador: WILEY
EN
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Recently, several studies have shown that the addition of a secondary element likes Al, Si, etc. to nitride and carbide binary systems such as Ti–N and Cr–N improved their structural and mechanical properties and also their thermal stability. In this study, we realized a comparison between the effects of aluminum or molybdenum addition on the properties of the Cr–N system. The (Cr,Al)N and (Cr,Mo)N films were deposited by RF dual magnetron sputtering. To control the aluminum and molybdenum contents in (Cr,Al)N and in (Cr,Mo)N films, respectively, we modified the Cr, Al and Mo target bias. The structural, morphological and composition analyses of the deposited films were carried out using X-ray diffraction (XRD) and SEM equipped with an energy dispersive spectroscopy (EDS) microanalysis. The variation of the residual stresses with the Al and Mo contents has been studied using the Newton’s rings method. The obtained Al contents in (Cr,Al)N deposited films varied between 0 and 51 at.% while the Mo contents in (Cr,Mo)N layers varied between 0 and 42 at.%. A morphological change from amorphous to columnar films has been observed with the addition of Al in the case of (Cr,Al)N coatings, while all the (Cr,Mo)N films presented a columnar structure. The residual stresses of the (Cr...

Comparison of CrAlN layers obtained with one (CrAl) or two targets (Cr and Al) by magnetron sputtering

NOUVEAU, Corinne; TLILI, Brahim; AKNOUCHE, Hamid; BENLATRECHE, Yacine; PATEL, Bhavesh
Fonte: Elsevier Publicador: Elsevier
EN
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The authors would like to thank the Regional Council of Burgundy, France for its funding and Michael Walock for his help in English revisions; The aim of this study is to compare the properties of CrAlN coatings obtained by magnetron sputtering with one (CrAl) or two targets (Cr and Al). The influence of parameters such as the target bias voltage, the working pressure, the deposition time and the bias voltage applied on the Cr or Al targets on the properties of the layers was studied. We characterized the films by X-ray Diffraction, Scanning Electron Microscopy, coupled with Energy Dispersive Spectroscopy, nanoindentation and their residual stresses were also determined. The optimal films obtained with both methods are well crystallized, well-adherent to the substrate, and contained similar amounts of Al (20–30 at.%). The optimal coatings synthesized with one target presented properties not as good as those realized with two targets. Nevertheless, films made with one target showed a lower frictional coefficient probably due to composition control. The lack of compositional control with the use of one target limits the optimization process. With two targets, we have greater control over the film composition. This leads to higher hardness...

W-Cr-C-N Nanocomposite Thin-Film Coatings via Reactive Magnetron Sputtering

WALOCK, Michael; ZOU, Yujiao; LAGADRILLERE, Denis; NOUVEAU, Corinne; STANISHEVSKY, Andrei
Fonte: Society of Vacuum Coaters Publicador: Society of Vacuum Coaters
EN_US
Relevância na Pesquisa
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While binary tungsten carbide can form smooth, hard films, these suffer from low fracture toughness. Tungsten nitride films are frequently harder, but are more brittle. Chromium nitride has excellent wear and oxidation resistance, but films often form with low hardness. Composites of these binary compounds offer a possibility to tailor the material for a desired combination of properties. To this end, we have used reactive RF-magnetron sputtering with Cr and WC targets to form quaternary composites, with nitrogen as the reactive gas. The coatings were deposited on Si, Ti, and steel substrates. The nitrogen partial pressure was varied to investigate the relationship between the film properties and the deposition conditions. Energy dispersive spectroscopy showed changes in the chemical composition as a result of the change in nitrogen partial pressure. X-ray diffraction illuminated the structure as either a solid solution with a B1 NaCl structure, or a nanocomposite with the average crystallite size under 11 nm. Optical interferometer revealed low compressive stresses. And nanoindentation established that the films are hard and adherent.; U.S. National Science Foundation (DMR-0806521) and the Regional Council of Burgundy, France

Silica-based Nano-coating on Zirconia Surfaces Using Reactive Magnetron Sputtering: Effect on Chemical Adhesion of Resin Cements

Cavalcanti Queiroz, Jose Renato; Massi, Marcos; Nogueira, Lafayette; Silva Sobrinho, Argemiro Soares da; Bottino, Marco Antonio; Oezcan, Mutlu
Fonte: Quintessence Publishing Co Inc Publicador: Quintessence Publishing Co Inc
Tipo: Artigo de Revista Científica Formato: 151-159
ENG
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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP); Processo FAPESP: 09/53584-4; Purpose: To compare the effect of silica (Si)-based nano-coating deposited by reactive magnetron sputtering (RMP) with that of conventional surface conditioning using metal/zirconia primer alone or after air-particle abrasion on the adhesion of resin cements to zirconia ceramic.Materials and Methods: Two hundred forty zirconia ceramic blocks (Cercon) were sintered, finished with 1200-grit SiC paper under water cooling, and cleaned ultrasonically in distilled water for 10 min. The blocks (4.5 mm x 3.5 mm x 4.5 mm) were randomly divided into 24 groups (n = 10) according to 3 testing parameters: a) resin cements (Multilink, Panavia F, RelyX U100), b) surface conditioning (no conditioning as control group; Metal/Zirconia Primer; air abrasion + Metal/Zirconia Primer; Si-based nanofilm + Monobond s); c) aging (no aging vs thermo cycling at 5 degrees C to 55 degrees C, 6000 cycles). The nanofilm was deposited by direct current using argon/oxygen plasma (8:1 in flux) on the zirconia surface. Resin cements were bonded to zirconia surfaces using polyethylene molds. The shear bond strength (SBS) test was performed using a universal testing machine (1 mm/min)...

Preparação e caracterização óptica de filmes nanocristalinos de GaAs:H depositados por RF magnetron sputtering

Costa, Wangner Barbosa da
Fonte: Universidade Estadual Paulista (UNESP) Publicador: Universidade Estadual Paulista (UNESP)
Tipo: Dissertação de Mestrado Formato: 79 f. : il.
POR
Relevância na Pesquisa
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Pós-graduação em Ciência e Tecnologia de Materiais - FC; Filmes nanocristalinos e amorfos de GaAs tem recentemente chamado a atenção de vários grupos de pesquisa devido as suas possíveis aplicações em novos dispositivos ópticos e eletrônicos. Igualmente atraentes são as novas propriedades físicas relacionadas com a estrutura nanocristalina e os efeitos da desordem na estrutura eletrônicas destes materiais. Entre as aplicações existentes, podemos citar o uso destes filmes como camadas anti-guia em lasers com emissão perpendicular à superfície, as camadas “buffer” em hetero-epitaxias de GaAs sobre Si, e os filtros interferométricos para a região do infravermelho. A preparação e a caracterização de filmes nanocristalinos de GaAs hidrogenados e não hidrogenados usando a técnica de RF magnetron sputtering foram focalizados neste trabalho. Um alvo de GaAs e uma atmosfera controlada contendo quantidades variáveis de argônio (Ar) e hidrogênio (H2) foram usadas na deposição do filme. Foi investigada a influência do fluxo de Ar e H2 na composição, estrutura e propriedades ópticas dos filmes. A influência da temperatura de substrato e potência de deposição também foi analisada. As técnicas de difração de raios-X e análise da energia de dispersão por emissão de raios-X (EDX)...

Influence of process parameters on the growth of pure-phase anatase and rutile TiO2 thin films deposited by low temperature reactive magnetron sputtering

Toku,H.; Pessoa,R.S.; Maciel,H.S.; Massi,M.; Mengui,U.A.
Fonte: Sociedade Brasileira de Física Publicador: Sociedade Brasileira de Física
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/09/2010 EN
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In this work is investigated the optimal conditions for deposition of pure- phase anatase and rutile thin films prepared at low temperatures (less than 150ºC) by reactive dc magnetron sputtering onto well- cleaned p- type Si substrates. For this, the variation of deposition plasma parameters as substrate- to- target distance, total gas pressure, oxygen concentration, and substrate bias were studied and correlated with the characteristics of the deposited films. The XRD analysis indicates the formation of pure rutile phase when the substrate is biased at voltages between - 200 and - 300 V. Pure anatase phase is only attained when the total pressure is higher than 0.7 Pa. Moreover, it's noticeable a strong dependence of surface roughness with parameters studied.

ELECTRICAL PROPERTIES OF Cr/CrN NANO-MULTILAYERS PRODUCED BY THE UNBALANCED MAGNETRON SPUTTERING TECHNIQUE

MARULANDA CARDONA,DIANA MARITZA; OLAYA FLOREZ,JHON JAIRO
Fonte: DYNA Publicador: DYNA
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/08/2011 EN
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Chromium nitride (CrN) films have been applied to several steels as protective coatings against wear and corrosion due to their excellent mechanical properties and corrosion resistance, and in the electronic field these films are commonly used due to their low electrical resistivity. However, it has been found that multilayers combining metal/ceramic films could enhance mechanical and electrical properties compared with their monolayer counterparts, due to the higher amount and interaction between interfaces. In this work, Cr/CrN nano-multilayers have been produced through the unbalanced magnetron sputtering technique with three different degrees of unbalance, in order to study the influence of this parameter on electrical properties. Cr/CrN multilayers with approximately 1 µm of total thickness and a bilayer period (Λ) of 200 nm, 100 nm, and 20 nm were produced at room temperature on H13 steel and silicon (100); and their microstructure and electrical properties as a function of the magnetic field were evaluated. The phase formation was characterized through x-ray diffraction, and results presented (111) and (200) preferred orientations for all the multilayers. Cross section images were obtained through scanning electron microscopy and a multilayer structure can be clearly seen.

UNBALANCED MAGNETRON SPUTTERING SYSTEM FOR PRODUCING CORROSION RESISTANCE MULTILAYER COATINGS

MARULANDA,DIANA; OLAYA,JHON JAIRO
Fonte: DYNA Publicador: DYNA
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/02/2012 EN
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In this work, an unbalanced magnetron sputtering system which allows for the production of corrosion resistance multilayer coatings is described. The major advantage of this system is that it combines features such as a multi-cathode setup, temperature control, control over the rotation of the sample holder, and the ability to change samples without breaking the vacuum. The system was tested with the production of Cr/CrN nanometric multilayers on AISI stainless steel 304 and silicon (100) substrates and the evaluation of its corrosion resistance. X-ray diffraction (XRD) was used in order to assess the crystalline microstructure and scanning electron microscopy (SEM) was used to characterize multilayer formation. The XRD results show (111) and (200) orientations for CrN multilayer films and the SEM results clearly show the formation of a multilayer structure. Corrosion resistance was evaluated through electrochemical studies and the results show that the Cr/CrN multilayer structure presents lower corrosion current and higher corrosion potential as compared to the stainless steel 304 substrate.

Polycristalline growth of zinc blende gallium arsenide layers by R.F. magnetron sputtering

Bernal Correa,R.; Montes Monsalve,J.; Pulzara Mora,A.; López López,M.; Cruz Orea,A.; Cardona,J.A.
Fonte: Sociedad Mexicana de Ciencia y Tecnología de Superficies y Materiales A.C. Publicador: Sociedad Mexicana de Ciencia y Tecnología de Superficies y Materiales A.C.
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/01/2014 EN
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Zinc-blende GaAs layers were prepared on (100) Si and glass substrates by r.f. magnetron sputtering. The morphology of GaAs layers is analyzed by means of atomic force microscopy (AFM) and scanning electron microscopy (FE-SEM), to determine the sample topography and growth type. The compositional analysis was performed by means of energy dispersive X-ray spectroscopy (EDS), in order to obtain information of the atomic percentages of the elements and their spatial distribution in the samples. The optical properties of the layers are discussed from the results of UV-Vis absorption, and Photoacoustic spectroscopy (PAS). Finally, the Raman shift of the GaAs phonon modes are studied as function of the penetration depth of laser wavelength used to excite the sample on Raman microscopy.

Characterization of nanostructured SnO2 films deposited by reactive DC-magnetron sputtering

Camacho-López,M. A.; Galeana-Camacho,J. R.; Esparza-García,A.; Sánchez-Pérez,C.; Julien,C. M.
Fonte: Sociedad Mexicana de Ciencia y Tecnología de Superficies y Materiales A.C. Publicador: Sociedad Mexicana de Ciencia y Tecnología de Superficies y Materiales A.C.
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/01/2013 EN
Relevância na Pesquisa
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Nanostructured tin oxide thin films were deposited on silicon and glass slides substrates by reactive DC-Magnetron sputtering using a tin target in a mixture of argon and oxygen gases. The substrate temperature was varied in the range from 53 to 243 ºC, keeping the other deposition parameters constant. The tin oxide films were characterized by: Scanning Electron Microscopy, Energy Dispersive Spectrometry, X Ray Diffraction, microRaman spectroscopy and UV-VIS spectroscopy. It was found that the substrate temperature has an effect mainly on the structural, morphological and optical properties of the thin films. At 53 and 90 ºC the tetragonal crystalline phase was obtained while a mixture of crystalline phases (o-SnO2 and t-SnO2) was obtained at 148, 185 and 243 ºC.

SnO2:F thin films deposited by RF magnetron sputtering: effect of the SnF2 amount in the target on the physical properties

de Moure-Flores,F.; Guillén-Cervantes,A.; Nieto-Zepeda,K.E.; Quiñones-Galván,J.G.; Hernández-Hernández,A.; de la L. Olvera,M.; Meléndez-Lira,M.
Fonte: Sociedad Mexicana de Física Publicador: Sociedad Mexicana de Física
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/08/2013 EN
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SnO2:F thin films were prepared by RF magnetron sputtering onto glass substrates using SnF2 as fluorine source. The films were deposited under a mixed argon/hydrogen atmosphere at a substrate temperature of 500°C. The X-ray diffraction shows that polycrystalline films were grown with a phases mixture of SnO2 and SnO. The optical transmittance is between 80 and 90%. The physical properties of the films suggest that SnO2 thin films grown with small SnF2 content in the target can be considered as candidates for transparent electrodes.