Structural, Electric and Thermoelectric Studies of CaFeO3 System
Abstract
Polycrystalline CaFeO3 samples were synthesized through solid state route at 1000 oC. The sintered samples were analyzed by XRD for crystal structure analysis. Electrical resistivity and seebeck coefficient were also measured for transport properties. The Rietveld analysis performed on the XRD data revealed that the sample is single phase with orthorhombic crystal symmetry. The space group was found to be pcmn. Power factor has been obtained from Seebeck Coefficient and electrical resistivity data. Electrical resistivity showed that conduction in the sample occurred through variable range hopping of the electrons. The negative Sign of Seebeck coefficient revealed that majority charge carriers in these samples are electrons. The properties determined make this material a potential candidate for electric and thermoelectric device applications.References
E. A. Smith, I. N. Lokuhewa, S. T. Misture, D. D. Edwards, “p-Type
thermoelectric properties of the oxygen deficient perovskite
Ca2Fe2O5 in the brownmillerite structure†J. Sol. Stat. Chem., vol.
, p. 1670, 2010.
L. A. Salam, R. D. Mathews and H. Robertson, “Fabrication of iron
disilicide (FeSi2) thermoelectric generator by the tape casting
method†Mat.& Design., vol. 20, p. 223, 1999.
W. Wunderlich, “NaTaO3 composite ceramics – A new
thermoelectric material for energy generation†J. Nucl. Mater., vol.
, pp. 57-61, 2009.
S. Xiao-ya, W. Li, C. Li-dong and C. Xi-hong, “Thermoelectric
properties of MxMo6Te8 (M=Ag, Cu)†Trans. Nonferr. Met. Soc.
China, vol. 19, p. 642, 2009.
K. Kurosaki, A. Kosuga, M. Uno and S. Yamanaka, “Thermoelectric
properties of Mo3Te4†J. All. & Comp. vol. 334, p. 317, 2002.
H.M. Rietveld, “A profile refinement method for nuclear and
magnetic structures†J. Appl. Cryst., vol. 2, p. 65, 1969.
H.D. Zhou and J. B. Goodenough, “Electronic behavior of three
oxygen non-stoichiometric Fe4+/Fe3+ oxoperovskites†J. Sol. Stat.
Chem., vol. 178 p. 3679, 2005.
W. Pitschke, H. Hermann and N. Mattern, “The influence of surface
determination by means of Rietveld analysisâ€, Powder Diffraction.,
vol.8, p. 74, 1993.
W.A. Dollase, “Correction of intensities for preferred orientation in
powder diffractometry : application of the March model†J. Appl.
Cryst., vol. 19, p. 267, 1986.
J. Matsuno, T. Mizaokawa, A. Fujimori, Y. Takeda, S. Kawasaki and
M. Takano, “Different routes to charge disproportionation
perovskites-type Fe Oxides†arXiv. Cond.mat/0207725v1[condmat.strr-el], 2002.
