TY - JOUR ID - 16087 TI - Thermoelectric properties of hot-pressed pellets of Al and Ti co-doped calcium cobalt oxides (Ca<sub>(3-x)</sub>Al<sub>x</sub>Co<sub>(4-y)</sub>Ti<sub>y</sub>O<sub>9+δ</sub>) JO - Advanced Materials Proceedings JA - AMP LA - en SN - 2002-4428 AU - K. Gupta, Raj AU - K. Mahapatro, Ajit AU - P. Tandon, Ram AD - Department of Physics and Astrophysics, University of Delhi, Delhi 110007, India Y1 - 2018 PY - 2018 VL - 3 IS - 2 SP - 103 EP - 107 KW - Electrical resistivity KW - thermoelectric materials KW - power factor KW - seebeck coefficient DO - 10.5185/amp.2018/848 N2 - This work demonstrates the achievement of high thermopower in the pellets of calcium cobalt oxide (Ca3Co4O9) co-doped with aluminium (Al) and titanium (Ti). The pellets of Ca(3-x)AlxCo(4-y)TiyO9+&delta; with x, y = 0.0, 0.1, 0.2, 0.3, 0.4, and 0.5, oxide ceramics are prepared using a hot-press machine by applying an uniaxial pressure of 70 MPa at a dwell temperature of850 &ordm;C. Microstructure imaging reveals compactness of good connectivity among grains with the estimated density using Archimedes principle suggests the formation of near perfect (99%) relative density for the new pelleted ceramics. All theco-doped samples exhibit lower electrical resistivity (r) values compared to pure Ca3Co4O9. The maximum Seebeck coefficient (S) of 177 &mu;V/K at 750 K is achieved for the pure Ca3Co4O9 sample. A significant improvement of 18% in the power factor (S2/r) is realized at 750 K in the co-doped samples containing 0.2 mol% of Al and Ti co-doping. The demonstration of significant thermoelectric properties of Ca(3-x)AlxCo(4-y)TiyO9+&delta; suggest that these materials could be utilized as promising active material in thermoelectrics. Copyright &copy; 2018 VBRI Press.&nbsp; UR - https://amp.iaamonline.org/article_16087.html L1 - https://amp.iaamonline.org/article_16087_d35319a6b35359db0cd7fd7eace80d9e.pdf ER -