Origins of dielectric relaxations in AgNb7O18 ceramic
| Autor: | Sana Ullah Asif, Jian Wang, Yinjie Qian, Wanbiao Hu, Jiyang Xie |
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| Rok vydání: | 2020 |
| Předmět: |
010302 applied physics
Materials science Valence (chemistry) Condensed matter physics Process Chemistry and Technology Coordination number Energy landscape 02 engineering and technology Dielectric 021001 nanoscience & nanotechnology 01 natural sciences Capacitance Surfaces Coatings and Films Electronic Optical and Magnetic Materials Condensed Matter::Materials Science visual_art 0103 physical sciences Materials Chemistry Ceramics and Composites visual_art.visual_art_medium Equivalent circuit Ceramic 0210 nano-technology Anisotropy |
| Zdroj: | Ceramics International. 46:23021-23026 |
| ISSN: | 0272-8842 |
| DOI: | 10.1016/j.ceramint.2020.06.078 |
| Popis: | The origins of the relaxor behavior and low-temperature dielectric relaxation processes in AgNb7O18 ceramic were studied and a new relaxation mechanism was proposed through combined bond valence energy landscape (BVEL) calculation and equivalent circuit modeling (ECM). The BVEL calculation suggests that the Ag1 displacement subjects to a double-well potential that originates from the anisotropic coordination symmetry and low coordination number at Ag1 site. The relaxor ferroelectric behavior, observed at 200 K ≤ T ≤ 270 K, is sensitive to thermal history and is ascribed to the Ag1 hopping in double-well potential. The temperature dependence of the matrix capacitance (obtained by ECM) is very similar with that of b axis (obtained by in situ XRD) at 123 K |
| Databáze: | OpenAIRE |
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