Estudo do acoplamento Magnetoelétrico em BaTiO3 contendo Fe
authors Carlos de Oliveira Amorim
supervisors Vitor Brás Sequeira Amaral; Fábio Gabriel Nazário Figueiras
thesis type Mestrado Integrado
abstract This work aims to understand the nature of the anomalous magnetic behaviors of BaTiO3 which has 113 ppm of Fe in Its composition from the reactants used to synthesize this material. Two sets of samples were prepared to try to understand whether the Fe influences the anomalous behavior observed in the third chapter of this work. One set of samples involved the preparation of 5 pellets barium titanate (with 113 ppm of Fe) with different thermal treatments. The second group consisted of 5 BaTiO3 single crystals commercially obtained, in which ion doping was made using different Fe concentrations. Structural characterization of these samples was made using X-ray diffraction, Raman spectroscopy, SEM and EDS. Finally we made the magnetic characterization by measuring M-T and M-H curves using a VSM and/or a SQUID. We concluded that the Magnetoelectric effect present in the BTO samples should occur because the iron oxide clusters which accumulate at the grain boundaries result in interface effects. We can say that this BaTiO3: Fe is an unconventional Multiferroic were the Fe can be used as a Magnetoelectric probe that can be used in the magnetic study of electric phase transitions of BaTiO3! Future work will be made using Mössbauer spectroscopy and PAC to determine the local magnetic nature of the magnetic compound involved in Magnetoelectric effect.
year published 2013