1. Intrinsically modified thermoelectric performance of alkaline-earth isovalently substituted [Bi2AE2O4][CoO2]y single crystals
- Author
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Binbin Zhang, Zheng-Bin Gu, Jian Zhou, Yu-Lei Chen, Shu-Hua Yao, Yan-Feng Chen, S. T. Zhang, Nian X. Sun, and Song-Tao Dong
- Subjects
Crystal ,Materials science ,Thermal conductivity ,Electrical resistivity and conductivity ,Seebeck coefficient ,X-ray crystallography ,Thermoelectric effect ,Analytical chemistry ,General Physics and Astronomy ,Mineralogy ,Thermoelectric materials ,Single crystal - Abstract
Alkaline-earth elements isovalently substituted into a [Bi2AE2O4][CoO2]y (AE2 = Ca2, Sr2, and CaSr) single crystal with a layered structure were grown by the optical floating zone method. Structural characterization by X-ray diffraction and electron microscopy showed that the layers were oriented perpendicular to the c-axis, as well as the growth of direction was parallel to the ab-plane. The thermoelectric properties, including the Seebeck effect, electrical conductivity and thermal conductivity were investigated. The results of the thermoelectric measurements showed that the full substitution of Ca for Sr in [Bi2Sr2−xCaxO4][CoO2]y has the best overall thermoelectric performance. Compared with the other two cases studied, the full Ca substituted crystal [Bi2Ca2O4][CoO2]y exhibits both reduced resistivity and thermal conductivity, but not a reduced Seebeck coefficient. The enhanced thermoelectric property in [Bi2Ca2O4][CoO2]y is mainly due to lower structural symmetry, which is confirmed by electron micro...
- Published
- 2013