Structure and microwave dielectric property relations in (Ba1−xSrx)5Nb4O15 system
| Autor: | Chien Chih Ou, Yi Chang Lin, Che Yi Su, Chi Yuen Huang, Chun Te Lee |
|---|---|
| Rok vydání: | 2007 |
| Předmět: |
Materials science
Condensed matter physics Relative permittivity Mineralogy Crystal structure Dielectric chemistry.chemical_compound symbols.namesake Lattice constant chemistry Materials Chemistry Ceramics and Composites symbols Electroceramics Strontium oxide Raman spectroscopy Temperature coefficient |
| Zdroj: | Journal of the European Ceramic Society. 27:2273-2280 |
| ISSN: | 0955-2219 |
| Popis: | The effects of strontium substitution for barium on the structure and microwave dielectric properties of Ba5Nb4O15 compounds is investigated using X-ray diffraction, Raman spectroscopy, and microwave dielectric properties measurement. The symmetric stretching vibration of Ba-rich compounds splits into two narrow Raman-active modes and indicates the existence of a strong anharmonic lattice. Nevertheless, the symmetry changes from P 3 ¯ m 1 to P 3 ¯ c 1 for the Sr-rich compounds. The relative permittivity (ɛr) and temperature coefficient of resonant frequency (τf) increases linearly with an increase of strontium content in Ba-rich compounds, but decreases in Sr-rich compounds. The transition of symmetry influences the variation of ɛr and τf. The behavior of ɛr and τf can also be correlated to the variation of symmetric stretching vibrations of NbO6 octahedra and (c/a) ratio of lattice parameter in the unit cell. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|
Full Text from ScienceDirect