Document Type : Research Article
Authors
Department of Physics and Astrophysics, University of Delhi, Delhi 110007, India
Abstract
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+δ 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 of
850 ºC. 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 the
co-doped samples exhibit lower electrical resistivity (r) values compared to pure Ca3Co4O9. The maximum Seebeck coefficient (S) of 177 μV/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+δ suggest that these materials could be utilized as promising active material in thermoelectrics. Copyright © 2018 VBRI Press.
Keywords
DOI:10.1016/j.scriptamat.2004.10.038
2.Terasaki;Sasago, Y.;Uchinokura, K.;Phys. Rev.B, 1997,56,
R12685–12687.
DOI:10.1103/PhysRevB.56.R12685
3.Masset, A.C. ;Michel, C.;Maignan, A.;Hervieu,M.;Toulemende,
O.;Studer, S.;Phys. Rev. B2000,62,166-175.
DOI:10.1103/PhysRevB.62.166
4.Thermoelectric Handbook: Macro to Nano; edited by D.M.Rowe
(CRC), 2005.
ISBN-13:978-0849322648
5.Gupta, R.K.;Sharma, R.;Mahapatro, A.K.;Tandon,R.P.;
Physica B, 2016, 483, 48-53.
DOI:10.1016/j.physb.2015.12.028
Madreb, M. A.;Sotelob, A.;Diezb,J. C.; Ceramics International
2013,39, 6051-6056.
DOI:10.1016/j.ceramint.2013.01.021
7.Shikano,M.;Funachashi, R.; Appl. Phys. Lett, 2003, 82, 1851.
DOI:10.1063/1.1562337
8.Song , X.; Chen,Y;Chen, S; Barbero, E; Thomas , E.L.;Barnes,
P.; Solid State Communication, 2012, 152, 1509-1512.
DOI:10.1016/j.ssc.2012.06.014
9.Prevel, M.;Perez, O.;Noudem, J.G.;Solid State Science, 2007, 9,
231.
DOI:10.1016/j.solidstatesciences.2007.01.003
10.Fergus J.W.; Journal of the European Ceramic Society, 2012,32,
525-540.
DOI:10.1016/j.jeurceramsoc.2011.10.007
11.Ning Y.,W.; Nong, V.; Pryds, N.; Linderoth S., Journal of Alloys
and Compounds, 2015, 638,127–132.
DOI:10.1016/j.jallcom.2015.02.185
12.Liu, H.Q.;Zhao, X.B.;Zhu, T.J.;Song, Y.;Wang, F.P.;Current
Applied Physics, 2009, 9, 409–413.
DOI:10.1016/j.cap.2008.03.010
13.Creon, N.;Perez, O.;Hadermann, J.;Chem. Mater. 2006,18,5355.
DOI:10.1021/cm061163aCCC
14.Zhang, F.P. ;Lu, Q.M.;Zhang, J.X.; PhysicaB Condensed
Matter,2009, 404(16),2142-2145.
DOI:10.1016/j.physb.2009.04.002
15.Semidubsky, D.;Jakes, V.;Jankovsky, O.;Leitner, J.;Sofer, Z.;
Hejtmanek, J.;J.solid state chem, 2012, 194, 199-205.
DOI:10.1016/j.jssc.2012.05.014
16.Delorme, F.;Martin, C.F.;Marudhachalam, P.;Guzman,
G.;Ovono, D.O.;Fraboulet, O.;Mater. Res. Bull,2012,47,
3287-3291.
DOI:10.1016/j.materresbull.2012.07.037
)