| About this Abstract |
| Meeting |
Materials Science & Technology 2019
|
| Symposium
|
Advanced Manufacturing, Processing, Characterization and Modeling of Functional Materials
|
| Presentation Title |
Microstructure and Thermoelectric Properties of [001]c Grain-aligned Ca3Co4O9 Ceramics Prepared by Template Grain Growth |
| Author(s) |
Zongmo Shi, Jie Xu, Feng Gao, Mengjie Qin |
| On-Site Speaker (Planned) |
Zongmo Shi |
| Abstract Scope |
Textured Ca3Co4O9 (CCO) thermoelectric ceramics with Bi2O3 additive were fabricated by tap casting method combining with template grain growth. The charge carrier and phonon scattering transport showed an anisotropy of the electrical resistivity and thermal conductivity. It revealed that the relative density increased from 92.1% to 96.5% because of liquid−phase sintering mechanism by adding Bi2O3. Hall carrier concentration and mobility were tuned by holding time, having profound influence on the transport of charge carriers. Electrical resistivity along the ab-plane was 3 times than c-plane. The electrical resistivity decreased and Seebeck coefficient increased from 110 μV/K to 190 μV/K with increasing of sintering temperature. Furthermore, the peak ZT value of 0.3 was obtained for sample sintered at 1173 K for 10 h, resulting from low thermal conductivity of 0.92 W/(m·K). The obtained results suggest that textured ceramics can dramatically improve thermoelectric properties of Ca3Co4O9. |