Propriedades estruturais e microestruturais de eletro-cerâmicas baseadas em BaTiO3

• Autor(a) principal: Silva, Mykaelle Cristina Oliveira
• Data de Publicação: 2018
• Tipo de documento: Trabalho de conclusão de curso
• Idioma: por
• Título da fonte: Repositório Institucional da UFU
• Texto Completo: https://repositorio.ufu.br/handle/123456789/24249
• topic: Materiais ferroelétricos; Ferroelectric materials; Perovskita; Perovskite; Titanato de bário; Barium titanate; Propriedades estruturais; Structural properties; Microestrutura; Microstructure; CNPQ::CIENCIAS EXATAS E DA TERRA::FISICA; CNPQ::CIENCIAS EXATAS E DA TERRA::FISICA::FISICA DA MATERIA CONDENSADA

Ferroelectric systems have been widely studied during the last years because of their excellent physical properties, which make them promissory materials for technological applications. In special, the barium titanate (BaTiO3) represents one of the electro-ceramic materials that is still manufactured at large scales for many applications in the electronic components market. The excellent physical properties, in particular the dielectrics (high dielectric permittivity values and low dielectric losses) make the BaTiO3 (BT) a fundamental material in the manufacture of multilayer ceramic capacitors (MLCs). The doping of BT with some elements added as impurities in its perovskite structure, implies in the change of some physical properties, which have increased the range of application of these materials as piezoelectric devices, thermistors and semiconductors. Among them, the erbium (Er3+) ion stand out because it provides some relevant characteristics to the BT ferroelectric system, such as optical properties. In this context, in order to understand some anomalous behaviors of this material, this work aims the investigation of the structural and microstructural properties of BT-based ferroelectric ceramics, modified with the Er3+ rare-earth ion, considering its influence on the system in different concentrations. The ceramics were synthesized by the Pechini’s Method (or Polymeric Precursors Method), which presents great advantages compared to conventional methods for synthesis of polycrystalline materials. For the study of structural properties the analysis were carried out by X-ray Diffraction (XRD) technique and using the Willimason-Hall method. On the other hand, for the microstructurals properties it was used the Scanning Electron Microscopy (SEM) technique for the observations and calculation of grains-size, as well as their morphology.