Process Dependent Thermoelectric Transport Properties Of Ca3Co4O9
Rapaka S C Bose, L Rangaraj, Abanti Nag
Volume 2, Issue 8, Page 485-491, Year 2017 | DOI: 10.5185/amp.2017/804
Keywords: Sol-gel processes, hot pressing, density, grain size
Abstract: The p-type thermoelectric material Ca3Co4O9 were synthesized by the sol-gel synthesis in the presence of complexing agent of citric acid and dispersant of polyethylene glycol 400, and followed by the uni-axial hot-pressing (HP) technique. Observation by X-ray diffraction revealed that the formation of phase pure sample on calcination at 1073 K for 4 h. Scanning electron microscopy indicated that the significant enhancement of the grain growth through HP technique. The density of the sintered pellets increased with an increase of applied pressure. The electrical resistivity was greatly reduced with an increase of the applied pressure, whereas the Seebeck coefficient was little increased with an increase of the applied pressure. As a result, the pellet treated by the HP technique under the condition of 1098 K, 25 MPa and 30 min showed a maximum power factor of about 498 μWm-1K-2 at 950K. Copyright © 2017 VBRI Press.