CT - DEMAT - Artigos publicados em periódicos
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Artigo Shear bond strength of metal/ceramic interface after different surface treattments: an in vitro study(International Journal of Science Dentistry, 2012) Pereira, Sílvia Fontes do Amaral; Gouvêa, Cresus Vinícius Depes de; Carvalho, Waldimir; Nascimento, Rubens Maribondo do; Andrade, Simone Caixeta de; Buschinelli, José Augusto de AlmeidaO objetivo do presente estudo in vitro foi verificar, através de teste de cisalhamento, a resistência de união da liga Wironia®light, à base de níquel-cromo sem berílio, sujeita a diferentes tratamentos de superfície, às cerâmicas Vita VM13 e Noritake. Foram confeccionados oitenta espécimes cilíndricos metálicos, com o auxílio de uma matriz de aço, nas dimensões de 4 mm de diâmetro por 4 mm de altura. Os espécimes foram divididos em oito grupos (n=10), de acordo com o tipo de tratamento superficial aplicado à liga metálica e com o tipo de cerâmica testada. Estes foram avaliados de acordo com os critérios de resistência ao cisalhamento e, com o auxílio de microscopia óptica, foi avaliada a área de cerâmica remanescente aderida ao metal após a fratura. Os corpos-de-prova do G6 (fabricados em Cerâmica Noritake com jateamento-26,401 ± 11,637 MPa) apresentaram maior resistência ao cisalhamento (p> 0,05) enquanto que os menores valores foram registrados no G4 (Cerâmica Vita com utilização de broca-13,440 ± 7,766 MPa). G6 (19425,4 μm2) apresentou a maior área de cerâmica aderida ao metal (p> 0,05) enquanto que o G4 (2310,2 μm2) apresentou a menor área. Concluiu-se que G6 obteve os valores mais altos de resistência ao cisalhamento e de remanescente cerâmico aderido à superfície metálica enquanto que o G4 obteve os valores mais baixos.Artigo NiO-CGO Composite for SOFC Anode: Synthesis and Characterization(Journal of Materials Science and Engineering, 2010) Cela, Beatriz; Macedo, Daniel Araújo de; Souza, Graziele Lopes de; Miranda, Auristela Carla de; Martinelli, Antonio Eduardo; Nascimento, Rubens Maribondo do; Paskocimas, Carlos AlbertoIn this work compounds of gadolinium-doped ceria, Ce0.9Gd0.1O1.95 (CGO) and NiO were synthesized by polymeric precursor method. NiO-Ce0.9Gd0.1O1.95 composite was attained by mixture of the powders of the both phases calcinated already. The precursor powders were characterized by simultaneous thermogravimetry-differential thermal analysis and the calcined materials were studied by X-ray diffraction, scanning electronic microscopy, Fourier transform infrared spectroscopy and dilatometry. The refinement of the diffraction data indicated that the powders were crystallized in the wanted phases. All the produced powders had nanometric and sub micrometric features. The produced composite showed good characteristics for the use as anode for SOFC.Artigo Avaliação da potencialidade de argilas do Rio Grande do Norte, Brasil. Parte-II: propriedades tecnológicas(Cerâmica Industrial, 2008) Dutra, Ricardo Peixoto Suassuna; Silva, Jaquelígia Brito da; Varela, Marcio Luiz; Nascimento, Rubens Maribondo do; Gomes, Uílame Umbelino; Paskocimas, Carlos AlbertoA primeira parte deste trabalho apresentou um estudo de caracterização de doze matérias-primas de diferentes localidades do estado do Rio Grande do Norte, a fim de indicar um uso específico de cada matéria-prima para a indústria cerâmica, bem como direcionar a formulação e o processamento. Esse trabalho objetiva dar continuidade ao trabalho anterior, com o estudo das propriedades tecnológicas das matérias-primas caracterizadas, visando estabelecer as limitações das argilas em relação à temperatura, às formulações e às características essenciais ao produto. Corpos-de-prova foram preparados por prensagem uniaxial sob pressão de 25 MPa, secos e queimados em um forno elétrico com taxa de aquecimento de 2 °C/min e resfriamento natural. As temperaturas utilizadas foram: 650, 750, 850, 950, 1050, 1150 e 1250 °C. Foram realizados ensaios de retração linear de queima, determinação da perda de massa, absorção de água, massa específica aparente e de resistência mecânica sob flexão a três pontos. Resultados confirmam que existem dois diferentes tipos de matéria-prima e cada uma exige um processamento diferenciado e específico.Artigo Analysis of the Deformation of Composite Materials of Scrapes of Tire and Latex with Temperature Variation(David Publishing, 2012) Ford, Elmo Thiago Lins Cöuras; Nascimento, Rubens Maribondo do; Mendes, José Ubiragi de Lima; Marques, Antonio Torres; Pereira, Celeste Margarida CorreiaThe great major applications of thermal isolation are in the strip of drops and averages temperatures (up to 180 ºC), which is used from aggressive materials to the nature, such as glass wool, rock wool, polystyrene, EPS among others. In spite of the effectiveness in the retention of the flow of heat, such materials possess considerable cost and they are discarded for long years to be decomposed. In that context, to adapt to the world politics about the preservation of the environment, a study began with intention of developing a material composite with thermal properties, originating from insulating industrial residues. In this research, the behavior of this composite was analyzed, when it submitted traction efforts. For this, a term-mechanic was used (DMA), where the composite was differentiated under variation temperatures. It was also certain that the gradient temperature of the composite was the source of heat, the conductivity and thermal diffusion. Consequently, the function of the answers of the system was possible to be observed with the deformation of the composite with the tension and temperature variation, as well as the temperature gradient for each proportion of the composite.Artigo Development of composite material from tire scrapes and latex for application in thermal insulation(Engenharia Térmica, 2009-12) Nascimento, Rubens Maribondo do; Ford, Elmo Thiago Lins Couras; Mendes, J. U. L.; Pereira, C. M. C.; Marques, A. T.Given the unquestionable need of environmental preservation of discarded industrial residues, the scrape of tires, have been seen as a salutary alternative for addictive in concrete, asphalt production and of other composites materials. In this work, grew a composite the base of scrape of tire as reinforcement and latex as matrix, to be used as insulating thermal in "cold" systems (0o C). Analyzed the acting of the material was what plays the thermal conservation when submitted the flow of heat. Verified the temperature profiles in the internal surfaces and it expresses of the composite as well as the temperature gradient in the same. As consequence, in function of the answers of the system, conclusions were reachedArtigo Influência da gipsita no surgimento de eflorescência em telhas cerâmicas(Cerâmica Industrial, 2009-08) Nascimento, Rubens Maribondo do; Monteiro, Celina Margarida de Oliveira Lima; Martinelli, Antonio EduardoA indústria de cerâmica vermelha é referência no Estado do Piauí. Constitui o maior pólo produtor localizado na capital, Teresina, principalmente, de telhas cerâmicas. Uma das principais patologias observadas nesses produtos é o surgimento de eflorescências. Este trabalho visa estudar a influência da gipsita no surgimento de eflorescências em telhas cerâmicas, utilizando padrões de produção da indústria local. As matérias-primas foram caracterizadas por FRX, DRX, ensaios térmicos e determinação de sais solúveis em sulfatos. Foram confeccionados corpos de prova por extrusão, adicionando-se percentuais de 1, 3 e 5% de gipsita à massa cerâmica, queimados a 850, 950 e 1050 °C. Após sinterização, os corpos de prova foram submetidos a ensaios tecnológicos e caracterização microestrutural. Os resultados demonstram que o sulfato de cálcio, oriundo da gipsita, provoca o surgimento de eflorescência. A amostra com adição de 1% de gipsita não apresentou eflorescência após queima. Os corpos de prova com 5% de gipsita apresentaram eflorescência de secagemArtigo Influência do teor de calcário no comportamento físico, mecânico e microestrutural de cerâmicas estruturais(Associação Brasileira de Cerâmica – ABCERAM, 2010) Nascimento, Rubens Maribondo do; Castro, R. J. S.; Martinelli, Antonio Eduardo; Soares, R. A. L.O estado do Piauí tem jazidas de argilas utilizadas para cerâmica vermelha estrutural que naturalmente estão contaminadas com veios de calcário, o que impede a sua exploração de forma adequada, principalmente para a produção de telhas. O presente trabalho tem o objetivo de verificar a influência do teor de calcário nas propriedades tecnológicas da cerâmica estrutural, visando definir um teor máximo de calcário admissível na massa cerâmica utilizando-se dos padrões de produção da indústria local. Para isso, foram caracterizadas as matérias-primas argila e calcário por FRX e DRX. Também foram conformados por extrusão e queimados na temperatura de 900 °C os corpos-de-prova com 0, 5, 10, 15 e 20% de teor de calcário, em seguida, realizados ensaios tecnológicos de retração linear, absorção de água e resistência mecânica à flexãoArtigo The effect of residence time on the tensile properties of superelastic and thermal activated Ni-Ti orthodontic wires(ABM, ABC, ABPol, 2011-08-05) Nascimento, Rubens Maribondo do; Britto, Kathia Maria Fosenca de; Spinelli, José Eduardo; Martinelli, Antonio EduardoSince the 1980s, different devices based on superelastic alloys have been developed to fulfill orthodontic applications. Particularly in the last decades several researches have been carried out to evaluate the mechanical behavior of Ni-Ti alloys, including their tensile, torsion and fatigue properties. However, studies regarding the dependence of elastic properties on residence time of Ni-Ti wires in the oral cavity are scarce. Such approach is essential since metallic alloys are submitted to mechanical stresses during orthodontic treatment as well as pH and temperature fluctuations. The goal of the present contribution is to provide elastic stress-strain results to guide the orthodontic choice between martensitic thermal activated and austenitic superelastic Ni-Ti alloys. From the point of view of an orthodontist, the selection of appropriate materials and the correct maintenance of the orthodontic apparatus are essential needs during clinical treatment. The present work evaluated the elastic behavior of Ni-Ti alloy wires with diameters varying from 0.014 to 0.020 inches, submitted to hysteresis tensile tests with 8% strain. Tensile tests were performed after periods of use of 1, 2 and 3 months in the oral cavity of patients submitted to orthodontic treatment. The results from the hysteresis tests allowed to exam the strain range covered by isostress lines upon loading and unloading, as well as the residual strain after unloading for both superelastic and thermal activated Ni-Ti wires. Superelastic Ni-Ti wires exhibited higher load isostress values compared to thermal activated wires. It was found that such differences in the load isostress values can increase with increasing residence timeArtigo Estudo da potencialidade da aplicação de uma argila contaminada com calcário na produção de placas cerâmicas(Associação Brasileira de Cerâmica, 2012-12) Nascimento, Rubens Maribondo do; Soares, R. A. L.; Castro, R. J. S.Na região da cidade de Teresina, PI, encontra-se uma grande quantidade de jazidas de argilas de queima vermelha usadas na produção de cerâmica estrutural, sendo o principal motivo da instalação de um pólo cerâmico nesta região. Porém muitas destas jazidas não estão sendo exploradas de forma adequada ou simplesmente abandonadas por causa da contaminação com calcário, sendo este o principal contaminante indesejável pelos ceramistas do pólo teresinense. Assim, esta pesquisa tem como objetivo avaliar a potencialidade de aplicação de uma argila com calcário na produção de placas de revestimento cerâmico de queima vermelha. Para isso foram caracterizadas uma massa cerâmica usada na produção de revestimento semiporoso e uma argila contaminada com calcário. As matérias-primas foram queimadas em forno industrial separadamente e em combinação nas proporções de 25%, 50% e 75% em peso da argila adicionada a massa industrial. Foram realizados nos corpos de prova queimados ensaios tecnológicos de retração linear, absorção de água e resistência mecânica. A microestrutura foi avaliada através de análise por difração de raios X. Os resultados mostraram potencialidade da utilização da argila contaminada com calcário em massa de revestimento cerâmicoArtigo Utilização de matérias primas argilosas no desenvolvimento de materiais cerâmicos especiais: parte I - caracterização(Revista Eletrônica de Materiais e Processos, 2012) Nascimento, Rubens Maribondo do; Alves Junior, Rubens; Dutra, Ricardo Peixoto Suassuna; Campos, Lizsandra Fernanda Araújo; Ferreira, H. S.; Lima, S. J. G.Este trabalho estuda o desenvolvimento de um novo tipo material com função térmica e acústica, para ser utilizado pelo setor da construção civil. Esse material, conformado por prensagem, será constituído por duas camadas: uma camada interna, de elevada porosidade e com função de isolante, e uma camada externa, caracterizada por baixa porosidade, a qual tem função estética e mecânica. Para o desenvolvimento deste material foi necessária à caracterização de diferentes matérias primas argilosa. Foram coletadas cinco diferentes amostras do litoral paraibano as quais foram caracterizadas com os seguintes ensaios: análise química, análise granulométrica, índice de plasticidade e análise térmica. Além disso, a massa específica aparente, a porosidade aparente e a retração linear das amostras queimadas foram determinadas Os resultados apontam que as amostras estudadas apresentam características diversificadas, e sugere a amostra denominada por amostra 4 para compor a parte externa do material e a amostra 1, por possui elevada porosidade e a alta temperatura de sinterização para ser utilizada na parte interna do materialArtigo Brazing of zirconia to titanium using Ag-Cu and Au-Ni filler alloys(Associação Brasileira de Soldagem, 2013-12) Nascimento, Rubens Maribondo do; Pimenta, Jean Senise; Buschinelli, José de Almeida; Martinelli, Antonio Eduardo; Remmel, JosephAdvanced ceramic is usually joined to metal by the well-known direct brazing process, where costly active filler alloys can be considered a limitation. Brazing using active-metal-free filler alloy as insert between the joint components is an attempt to overcome it. The active metal diffusion from the titanium member through the bulk of molten filler to the ceramic was responsible to produce an active filler alloy in loco and promote reduction of the zirconium oxide to improve wetting on the ceramic surface. Unalloyed titanium was joined in a high-vacuum furnace (<3x10-5 mbar) to yttria-tetragonal zirconia polycristals (Y-TZP) and zirconia partially stabilized with magnesia (Mg-PSZ), where commercial fillers Ag-28Cu and Au-18Ni with respective thermal cycles were evaluated. Helium gas leak detection test was performed at the ceramic/metal interface at room temperature; samples from reliable vacuum tight joints were examined by microstructural analysis techniques and energy dispersive X-ray analysis at the joint cross-section. Tight joints were produced with eutectic Ag-Cu filler, revealing an intermetallic layer and a dark reaction layer near the ceramic surface; titanium diffusion was efficient for superficial chemical interactions between individual components. Brazing joints were also tested using three-point flexure testingArtigo One-step synthesis of composite electrolytes of Eu-doped ceria and alkali metal carbonates(Elsevier, 2013-12-13) Nascimento, Rubens Maribondo do; Rajesh, Surendran; Macedo, Daniel Araújo de; Souza, Graziele Lopes de; Figueiredo, Filipe Miguel Henriques Lebre Ramos; Marques, Fernando M. B.Europium-doped ceria (EDC, Ce0.9Eu0.1O2 d)/alkaline carbonate (LNC, (Li,Na)2CO3) composite ceramics prepared through a one-step citrate-based route were analyzed by powder X-ray diffraction, infrared and laser Raman spectroscopies as well as scanning and transmission electron microscopy. The electrochemical behavior of the electrolyte material was studied by impedance spectroscopy in air, CO2 and N2 þ H2 (90/10 vol%, respectively) gas mixtures, in the temperature range 300e600 C. The sub micrometric and even nanosized ceramic particles appeared as merged inside the mixed carbonates, with modest grain to grain necking. The EDC/LNC composite electrolytes showed a conductivity of 0.27 S cm 1 at 600 C in air, amongst the best ever reported, exceeding the usual requirements for fuel cell applicationsArtigo Effect of cold plasma treatment on recycled polyethylene/kapok composites interface adhesion(Composite Interfaces, 2018-11-26) Feitor, Michele Cequeira; Macedo, Murilo José Pereira; Mattos, Adriano Lincoln Albuquerque; Costa, Thércio Henrique de Carvalho; Ito, Edson Noriyuki; Melo, José Daniel DinizComposites from recycled polyethylene and kapok fibers were pre- pared using untreated and plasma-treated fibers. Flow properties, mechanical properties and fracture morphology were analyzed in order to evaluate the effects of cold plasma treatment on kapok fibers to improve interfacial bonding between fibers and matrix. Melt flow rate (MFR) measurements indicated a reduction in flow rate of the polymer with the addition of kapok fibers. Storage modulus increased with fiber addition and this effect was more significant when plasma- treated fibers were used. Tanδ obtained from viscoelastic characteriza- tion also suggested improvements in fiber/matrix interface as a result of plasma treatment. Addition of kapok fibers to polyethylene pro- duced a reduction in onset decomposition temperature determined from thermogravimetry curve. However, the decrease in temperature observed does not limit composite processing. Furthermore, the degree of crystallinity of polyethylene increased with the addition of untreated fibers and reduced when plasma treated fibers were added. Morphological analysis of failure surface by Field Emission Gun Scanning Electron Microscopy (FEGSEM) suggest that fiber/matrix adhesion was clearly improved when plasma treated fibers were used. Thus, the oxygen cold plasma treatment proved to be an effec- tive non-polluting approach to enhance matrix/fiber adhesion in poly- ethylene/kapok fiber composites, as opposed to chemical treatments.Artigo In2O3 microcrystals obtained from rapid calcination in domestic microwave oven(Elsevier, 2010) Motta, Fabiana Villela da; Lima, Renata C.; Marques, Ana Paula de Azevedo; Leite, Edson Roberto; Varela, José A.; Silva, Elson Longo daThe simple way to prepare In2O3 microcrystals is reported in this paper. The precursor, In(OH)3 microstructures, were obtained using the Microwave-Assisted Hydrothermal (MAH) Method. By annealing as-prepared In(OH)3 precursor at 500 °C for 5 min in a domestic microwave oven (MO), In2O3 microcrystals were prepared, inheriting the morphology of their precursor while still slightly distorted and collapsed due to the In(OH)3 dehydration process which was studied by thermal analysis. The In(OH)3 and In2O3 were characterized using powder X-ray diffraction (XRD), field emission scanning electron microscopy (FE-SEM) and Raman spectroscopy. These techniques confirm the chemical dehydration of In(OH)3 and the formation of In2O3 powders. The domestic MO promotes a rapid structural organization as compared with a CF (conventional furnace). The MAH method and the subsequent annealing in a domestic MO were shown to be a low cost route for the production of In2O3, with the advantages of lower temperature and smaller timeArtigo Indium hydroxide nanocubes and microcubes obtained by microwave-assisted hydrothermal method(Elsevier, 2010) Motta, Fabiana Villela da; Lima, R. C.; Marques, Ana Paula de Azevedo; Li, Maximo Siu; Leite, Edson Roberto; Varela, José A.; Silva, Elson Longo daSingle crystalline indium hydroxide (In(OH)3) architectures were prepared by a rapid and efficient microwave-assisted hydrothermal (MAH) method using indium chloride as the precursor. Nanostructures were obtained at a low temperature (140 °C with a time of 1 min). In(OH)3 samples were prepared at the same temperature for 8 with a time of 64 min. Using this method, In(OH)3 samples were obtained at milder conditions of temperature and time compared to the conventional hydrothermal method. Field emission scanning electron microscopy images confirm that these samples are composed of 3D nanocubic, microcubic and irregular structures of about 70 nm to 5 μm in size. Fourier transform Raman spectroscopy and photoluminescence (PL) measurements were used to characterize the productsArtigo Characterization and acidic properties of AlMCM-41 prepared by conventional and post-synthesis alumination(Australian Journal of Chemistry, 2015) Nascimento, Rubens Maribondo do; Costa, Maria José Fonseca; Chellappa, Thiago; Araujo, Antonio Souza de; Fonseca, Viviane Muniz; Fernandes Júnior, Valter José; Pacheco, Jose G. A.The catalysts analysed in the current work are variations of MCM-41. The properties of these highly ordered mesoporous aluminosilicates were adjusted by an isomorphous substitution of Si by a trivalent cation, in this case Al3þ, generating catalysts of the AlMCM-41 type. The materials were synthesized with a silicon/aluminium ratio of 40, through two methods of impregnation of the metal: conventional and post-synthesis alumination. With the aim of determining the density of the acid sites of the Al40MCM-41 prepared by post-synthesis and conventional alumination, studies of the adsorption of n-butylamine probe molecule were carried out. Further, the studied material was characterized by thermogravimetry measurements, providing the profile of decomposition of the samples, which allowed calculation of the densities of the acid sites. The model-free kinetic algorithms were applied in order to determinate conversion and apparent activation energy. Comparison of energy-dispersive X-ray fluorescence and X-ray photoelectron spectroscopy measurements indicated that the post-synthesis method was more favourable based on the metal positioning, ‘anchored’ in the surface of the catalyst. The textural properties of the calcined Al40MCM-41 prepared by post-synthesis and conventional alumination were characterized by X-ray diffraction, N2 isothermal adsorption measurements (Brunauer– Emmett–Teller and Barrett–Joyner–Halenda), transmission electron microscopy, and X-ray photoelectron spectroscopy.Artigo Use of sewage sludge as raw material in the manufacture of roofs(Anais da 2ª Conferência Internacional de Ciências Civis, Materiais e Ambientais Série: Avanços na Pesquisa de Engenharia, 2015) Nascimento, Rubens Maribondo do; Ingunza, Maria Del Pilar Durante; Lima, Andressa DantasThe present study verifiesthe possibility of incorporating sewage sludgein the production ofceramic massfor ceramicroof tiles. Domestic sewage sludge and clay from ceramic industries of the northeastregion of Brazil were used. The raw materials were chemically and mineralogically characterized. Seven hundred and fifty tiles were manufactured using different concentrations of sludge (2%, 4%, 6%, 8% and 10% of sludge dry mass). The high amount of organic material (71%) from the sludge shows itself as being main factor onaffecting the quality of roof tiles. The increaseddosage of sludge implies a linear tendency of increased absorption and decreasedload rupture on flexion.Results haveshown the possibility of using nearly 4% of sludge (dry matter) on ceramic mass to manufacture roof tiles with no interferencein itsfinal product properties,in compliancewith current international standards.Artigo Electrical conductivity and microstructure of NiO-CGO composites prepared by one-step synthesis(IOP Publishing, 2013-04-01) Nascimento, Rubens Maribondo do; Macedo, Daniel Araújo de; Figueiredo, Filipe Miguel Lebre; Patrício, Sónia Gonçalves; Martinelli, Antonio Eduardo; Paskocimas, Carlos Alberto; Marques, Fernando Manuel BicoThe correlation between the microstructure and electrical properties of NiO-Ce0.9Gd0.1O1.95 (NiO-CGO) composites prepared by a one-step synthesis method is reported in the present work, and compared to conventional samples synthesized by mechanically mixing commercial powders. Samples sintered between 1350 and 1450 °C had their microstructures and electrical properties investigated by scanning electron microscopy (SEM) and impedance spectroscopy. The total electrical conductivity in the range of 100 – 500 °C of one-step composites is more than one order of magnitude higher than for conventional material. This result is associated to the presence of a network of well-connected and homogeneously distributed NiO grains shown by SEM for the one-step composite, which is responsible for its improved percolative behavior and lower activation energy (0.24 eV at 250 – 650 °C).Artigo Síntese e caracterização de ferrita de níquel e níquel-zinco pelo método de polimerização de complexos(69° Congresso Anual da ABM - Internacional, 2014) Nascimento, Rubens Maribondo do; Assis, Raimison Bezerra de; Valcacer, Samara Melo; Silva, Camila Cruz da; Silva, Ariadne de Souza; Delmonte, Maurício Roberto Bomio; Paskocimas, Carlos Alberto; Gomes, Uílame Umbelino; Motta, Fabiana Villela daFerritas de níquel-zinco são materiais cerâmicos ferrimagnéticos com estrutura cristalina cúbica do tipo espinélio, pertencente ao grupo espacial Fd3m, sendo uma solução sólida de composição NiO, ZnO e Fe2O3. O método de polimerização de complexos tem enorme potencial para obtenção de cerâmicas magnéticas, por se tratar de um processo simples, que se origina a partir de materiais com elevado grau de pureza, o que leva à obtenção de pós com elevada homogeneidade química e elevada área superficial. Este trabalho tem como objetivo avaliar as características estruturais e morfológicas das ferritas Ni0,25Zn0,75Fe2O4 e NiFe2O4 obtidas através do método polimerização de complexos. A solução foi submetida a uma temperatura final de 120°C até a formação da resina, pirolisada a uma temperatura de 350°C durante 2 horas e calcinada a 500°C durante 2 horas. Os pós resultantes foram caracterizados por difração de raios X (DRX), análises térmicas (TG/ DSC) e microscopia eletrônica de varredura (MEV). Os resultados do DRX das duas composições apresentaram formação de fase majoritária ferrita. Os resultados das micrografias obtidas por MEV mostraram a formação de partículas aglomeradas com placas longitudinais para ambas composições, sendo características microestruturais importantes para aplicação magnética. O método de polimerização de complexos se apresentou como um método promissor para obtenção de pós cerâmicos de ferrita de níquel e níquel-zinco para aplicação magnética.Artigo Room temperature photoluminescence of BCT prepared by Complex Polymerization Method(Elsevier, 2010) Motta, Fabiana Villela da; Marques, Ana Paula de Azevedo; Espinosa, José Waldo Martínez; Pizani, Paulo Sérgio; Silva, Elson Longo da; Varela, José A.It was used the Complex Polymerization Method to synthesize barium calcium titanate powders (BCT). Crystalline Ba0.8Ca0.2TiO3 perovskite-type phase could be identified by X-ray diffraction and confirmed by Raman spectroscopy in the powders heat treated at 600 °C. Inherent defects, linked to structural disorder, facilitate the photoluminescence emission. The photoluminescent emission peak maximum was around of 533 nm (2.33 eV) for the Ba0.8Ca0.2TiO3. The photoluminescence process and the band emission energy photon showed dependence of both the structural order–disorder and the thermal treatment history. The results revealed that Ba0.8Ca0.2TiO3 (BCT20) is a highly promising candidate material for optical applications.