New high temperature dielectrics: Bi-free tungsten bronze ceramics with stable permittivity over a very wide temperature range
| Autor: | David A. Hall, Zabeada Aslam, Stuart Micklethwaite, Thomas Brown, Thomas E. Hooper, Yizhe Li, Andy Brown, Steven J. Milne |
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| Rok vydání: | 2021 |
| Předmět: |
010302 applied physics
Permittivity Materials science Doping Analytical chemistry Relative permittivity chemistry.chemical_element 02 engineering and technology Dielectric Atmospheric temperature range Tungsten 021001 nanoscience & nanotechnology 01 natural sciences chemistry visual_art 0103 physical sciences Materials Chemistry Ceramics and Composites visual_art.visual_art_medium Dielectric loss Ceramic 0210 nano-technology |
| Zdroj: | Brown, T, Brown, A P, Hall, D A, Hooper, T E, Li, Y, Micklethwaite, S, Aslam, Z & Milne, S J 2020, ' New High Temperature Dielectrics: Bi-free tungsten bronze ceramics with stable permittivity over a very wide temperature range ', Journal of the European Ceramic Society . https://doi.org/10.1016/j.jeurceramsoc.2020.10.034 |
| ISSN: | 0955-2219 |
| DOI: | 10.1016/j.jeurceramsoc.2020.10.034 |
| Popis: | High relative permittivity, er, over a very wide temperature range, −65 °C to 325 °C, is presented for ceramics designed to be compatible with base metal electrode multilayer capacitor manufacturing processes. We report a ≥ 300 °C potential Class II capacitor material, free from Bi or Pb ions, developed by doping Sr2NaNb5O15 with Ca2+, Y3+ and Zr4+ ions, according to the formulation Sr2−2zCazYzNaNb5-zZrzO15. For sample composition z = 0.025, er values are 1565 ± 15 % (1 kHz) from −65 °C to 325 °C. At a slightly higher level of doping, z = 0.05, er values are 1310 ± 10 % from −65 °C to 300 °C. Values of the dielectric loss tangent, tanδ are ≤ 0.025 from −60 °C to 290 °C, for z = 0.025, with tanδ increasing to 0.035 at 325 °C. Microstructural analyses exclude core-shell mechanisms being responsible for the flattening of the er –T response. |
| Databáze: | OpenAIRE |
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