Estudo das propriedades dielétricas da matriz Ca Bi4Ti4O15(CBT) adicionada com Bi2O3 para aplicação em dispositivos de RF e microondas

• Ano de defesa: 2012
• Autor(a) principal: Freitas, Daniel Barros de
• Tipo de documento: Dissertação
• Tipo de acesso: Acesso aberto
• Idioma: por
• Palavras-chave em Português: Teleinformática; Antenas (Eletrônica); Raios X - Difração; Ferroeletricidade
• Link de acesso: http://www.repositorio.ufc.br/handle/riufc/3854

With the recent advances in telecommunications industry, it’s increasingly required the development of materials which have high values of dielectric constant, low dielectric loss and a good thermal stability. Many materials for radio frequency and microwaves utilization have been largely used in a variety of applications in these segments. From these applications, the latest technology generally use ceramics with low sintering temperature, low melting point materials, in addition to the aforementioned characteristics. Dielectric ceramics based on Bismuth are candidates as low temperature sintering materials and have been studied extensively. This work presents the development and characterization of ceramic series CaBi4Ti4O15 (CBT) with addition of bismuth trioxide, which is currently known for its excellent dielectric properties, mostly by its high dielectric constant values. These series were produced by the use of conventional ceramic method or method of solid state, with the use of mechanical grinding of high energy and heat treatment. After the synthesis, was added the bismuth trioxide in different concentrations to improve the electrical characteristics of ceramic CBT. The Structural characterization was showed by X-ray Diffraction with Rietveld Refinement. A study of the morphology was accomplished by scanning electron microscopy (SEM). Experiments were performed to verify the behavior of dielectric samples, radio frequency and microwaves. In general we can realize that this ceramic standard mold presents desirable characteristics for its application in the manufacture of electronic devices such as capacitors and dielectric resonator antennas.