56 documents found, page 1 of 6
Dielectric resonator antennas (DRA) analysis of matriz alloy based on Ca(Nb2/3L...
Costa, Antonia Daniele Souza Bruno; Costa, Rodrigo Carvalho Souza; Amarante, Francisco Welton de Oliveira; Saraiva, Gilberto DantasIn this study the electroceramics based on Ca(Nb2/3Li1/3)xTi1−xO3-δ, for x between 0 and 1, were prepared by the traditional solid state method. DRA in cylindrical shape with probe-feed cylindrical were investigated. The dielectric permittivity and loss of the CNLTOX alloy were analyzed in the region of 2 to 4.5 GHz. The frequency response around the first mode (HEM11δ) was determined by the HFSS (High Frequenc...
Comportamento dielétrico, elétrico e estrutural das cerâmicas Mg4Nb2O9 para apl...
Silva Filho, José Miranda da; Sales, Juscelino Chaves; Oliveira, Ronaldo Glauber Maia de; Freitas, Daniel Barros de; Rodrigues Junior, Cauby AmorimAs amostras de Mg4X2O9 (X=Nb, Ta) foram preparadas pelo método de reação de estado solido. Com o objetivo de estudar as propriedades dielétricas para aplicações em dispositivos microondas através das adições de V2O5 e Bi2O3 em diferentes porcentagens. Seram analisados os impactos dessas adições visando à melhoria de parâmetros elétricos relevantes como constante dielétrica e fator de qualidade. As adições de B2...
Análise dielétrica e magnética da eletrocerâmica Ba2Co2Fe12O22 adicionada com P...
Pires Júnior, Guilherme Francisco de Morais; Rodrigues, Herbert de Oliveira; Sales, Juscelino Chaves; Ferreira, Alisson da ConceiçãoThe objective of this work is to study the dielectric and magnetic properties of electroceramics (Ba2Co2Fe12O22 - Co2Y) added with (3; 5 and 10 wt%) of PbO in order to promote better dielectric and magnetic properties for applications in electronics. Phase Co2Y was obtained through the method of solid-state reaction. The analysis for X-Ray Diffraction (XRD) using Rietveld refinement confirmed the formation of i...
Eletrocerâmica multiferróica: produção e caracterização por difração de raios-x...
Rodrigues, Herbert de Oliveira; Pires Júnior, Guilherme Francisco de Morais; Sales, Juscelino Chaves; Sancho, Emmanuelle de OliveiraThis paper aims to present and discuss the results of measurements of X-ray diffraction performed to characterize electroceramics composite material BiFeO3 (BFO) with additives bismuth oxide (Bi2O3) and lead oxide (PbO). BFO matrix was produced by the solid-state reaction standard method. The additives were used at a concentration of 10% by weight. The binders used to improve the densification of the samples we...
Estudo estrutural e dielétrico da matriz cerâmicas Na2Nb4O11 adicionada de TIO2
Romeu, Mairton Cavalcante; Oliveira, Ronaldo Glauber Maia de; Sales, Antônio Jefferson Mangueira; Silva Filho, José Miranda da; Sales, Juscelino ChavesA fase Na2Nb4O11 tem se mostrado com grande potencial para aplicações em componentes eletromagnéticos. Na literatura encontramos estudos nos quais suas propriedades ferroelétricas são examinadas. O objetivo deste trabalho foi realizar uma analise estrutural e dielétrica da matriz cerâmica Na2Nb4O11 com a adição de TiO2, nas proporções ( 0, 2% em massa) em uma faixa de frequência (100 Hz - 1 MHz) em temperatura ...
Estudo dielétrico da cerâmica baseada no niobato de estrôncio e cobalto ((Sr2Co...
Morais, José Eduardo Vasconcelos de; Castro, Armando José Neves de; Silva, Marcelo Antonio Santos da; Sales, Juscelino ChavesApplications of ceramic dielectric in the telecommunications has been growing in recent years due to the dielectric properties presented by ceramic in RF and microwave ranges compared to metallic materials. Perovskite-type ceramics has stimulated the interest because of its features dielectric ceramic differentiated from other ceramics groups. The SCNO (Sr2CoNbO6) is a perovskite-type mixed and that will be the...
Estudo das propriedades diéletricas do SrBi4Ti4O15 (SBTi) dopado com V2O5
Rodrigues Junior, Cauby Amorim; Silva Filho, José Miranda da; Freitas, Daniel Barros de; Oliveira, Ronaldo Glauber Maia deThe SrBi4Ti4O15 (SBTI) is a typical cation-deficient perovskite. This work aims to study the electrical and dielectric properties of the material SBTI doped vanadium oxide (V2O5). The SBTI was prepared by the ceramic method. The powders of bismuth oxide (Bi2O3), titanium oxide (TiO2) and strontium carbonate (SrCO3) were weighed stoichiometrically and mixed. The powders were mixed and milled calcined and then si...
Caracterização dielétrica da cerâmica ferroelétrica Ti0.4Fe0.3Nb0.3O2 (TFNO) co...
Sousa, Djalma Gomes de; Silva Filho, José Miranda da; Sales, Juscelino Chaves; Silva, Marcelo Antonio Santos da; Sales, Antônio Jefferson MangueiraFrom of the powder oxides, Fe2O3 (Sigma-Aldrich, 99.0%), Nb2O5 (Sigma-Aldrich, 99.99%) and TiO2 (Vetec, 99.8%), was done synthesis, by solid state reaction method of the Ti0.4Fe0.3Nb0.3O2 (TFNO) ceramic. Following the stoichiometric proportions the mixed oxides were ball milled for 7h and calcined at 1075°C for 4h. TFNO phase was confirmed from X-ray diffraction technique (XRD) and Rietveld refinement. Then, we...
Estudo das propriedades dielétricas em função da temperatura da cerâmica binbo4...
Sales, Antônio Jefferson Mangueira; Pires Júnior, Guilherme Francisco de Morais; Sousa, Djalma Gomes de; Rodrigues Junior, Cauby AmorimThe Bismuth Niobate (BiNbO4) or BNO, has been explored as a dielectric material with great potential for LTCCs (Low temperature co-fired ceramic) multilayer. The LTCCs are microelectronic devices that have as their point differential synthesis, and the structural support along with their sintered ceramic resistive components, conductors and dielectrics less than 1000 ºC and monolithically. In order to improve t...
Síntese e caracterização da cerâmica BNO (BiNbO4) adicionada com 3% de ZnO
Sales, Antônio Jefferson Mangueira; Pires Júnior, Guilherme Francisco de Morais; Rodrigues, Herbert de Oliveira; Sales, Juscelino ChavesThis work describes the synthesis and study of the structural characterization of ceramic BiNbO4 and density behavior when added 3% by weight of ZnO with a view to use in capacitors. The manufacture of BiNbO4 was made by conventional ceramic method. The powders were milled for two hours, calcined at 850 ° C for 3 h and characterized by XRD with Diffractometer Rigaku DMAXB of Co- radiation. A more detailed XRD ...