Detalhes bibliográficos
| Ano de defesa: |
2012 |
| Autor(a) principal: |
Silva, Ariel Nonato Almeida de Abreu
 |
| Orientador(a): |
PASCHOAL, Carlos William de Araújo |
| Banca de defesa: |
Silva, Eder Nascimento
|
| Tipo de documento: |
Dissertação
|
| Tipo de acesso: |
Acesso aberto |
| Idioma: |
por |
| Instituição de defesa: |
Universidade Federal do Maranhão
|
| Programa de Pós-Graduação: |
PROGRAMA DE PÓS-GRADUAÇÃO EM FÍSICA/CCET
|
| Departamento: |
FISICA
|
| País: |
BR
|
| Palavras-chave em Português: |
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| Palavras-chave em Inglês: |
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| Área do conhecimento CNPq: |
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| Link de acesso: |
http://tedebc.ufma.br:8080/jspui/handle/tede/743
|
Resumo: |
In this work we investigated the vibrational and dielectric properties of the ceramic Bi₃Fe₀ ₅Nb₁ ₅O₉(BFN) at room temperature by using the Raman and infrared spectroscopic techniques along with classical lattice dynamics calculations. Concerning the Raman modes, fifteen vibrational modes at room temperature, were observed and classified based on performed lattice dynamics calculations. The temperature dependent Raman spectra showed clearly the ferroelectric phase transition in BFN at around 250 ° C, as discussed in the literature. The dielectric properties as well as Longitudinal (LO) and Transverse (TO) optical modes were obtained by adjusting the reflectivity spectrum of BFN at room temperature. We calculated static dielectric constant as εs = 30, which is relatively larger than the minimum value required for passive devices used in microwave electronics (εs > 10). Finally, we determined the dielectric loss in the microwave region yielding a quality factor Q = 2040 (10 GHz). |
