TY - GEN
T1 - Crystal structure and thermoelectric properties of the composite crystal [(Ca1-xSrx)2CoO3]pCoO2
AU - Miyazaki, Y.
AU - Miura, T.
AU - Ono, Y.
AU - Akashi, T.
AU - Goto, T.
AU - Kajitani, T.
N1 - Publisher Copyright:
© 2002 IEEE.
PY - 2002
Y1 - 2002
N2 - Polycrystalline samples of [(Ca1-xSrx)2CoO3]pCoO2 with 0 ≤5 x≤0.25 have been synthesized at 920°C in flowing oxygen gas. The modulated crystal structure of the samples has been determined in accordance with a four-dimensional formalism from powder neutron diffraction data. With increasing x, the modulation amplitudes in Co-Co conduction paths become less marked. The non-doped sample (x=0) exhibits the resistivity ρ =15 mΩcm and the thermoelectric power S=130 μV/K at 300 K. Both the ρ and S values decrease with x but the decrease in ρ values is steeper than that of the S values. The power factor S2/ρ increases with x, from 1.1×10-4 W/mK2 (x=0) to 1.4×10-4 W/mK2 (x=0.20) at 300 K. This improvement in thermoelectric performance can be explained in terms of the reduction of displacive modulation of the Co-Co conduction paths in the CoO2 sheets.
AB - Polycrystalline samples of [(Ca1-xSrx)2CoO3]pCoO2 with 0 ≤5 x≤0.25 have been synthesized at 920°C in flowing oxygen gas. The modulated crystal structure of the samples has been determined in accordance with a four-dimensional formalism from powder neutron diffraction data. With increasing x, the modulation amplitudes in Co-Co conduction paths become less marked. The non-doped sample (x=0) exhibits the resistivity ρ =15 mΩcm and the thermoelectric power S=130 μV/K at 300 K. Both the ρ and S values decrease with x but the decrease in ρ values is steeper than that of the S values. The power factor S2/ρ increases with x, from 1.1×10-4 W/mK2 (x=0) to 1.4×10-4 W/mK2 (x=0.20) at 300 K. This improvement in thermoelectric performance can be explained in terms of the reduction of displacive modulation of the Co-Co conduction paths in the CoO2 sheets.
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U2 - 10.1109/ICT.2002.1190306
DO - 10.1109/ICT.2002.1190306
M3 - Conference contribution
AN - SCOPUS:84949794445
T3 - International Conference on Thermoelectrics, ICT, Proceedings
SP - 226
EP - 229
BT - Proceedings ICT 2002
PB - Institute of Electrical and Electronics Engineers Inc.
T2 - 21st International Conference on Thermoelectrics, ICT 2002
Y2 - 25 August 2002 through 29 August 2002
ER -