Abstract
We have synthesized a series of layered cobaltite Bi2Sr2−xCaxCo2Oy (0≤x≤0.3). Reduced resistivity was observed with x≤0.2 due to the possible chemical pressure induced charge transfer between the Bi2Sr2O4 layer and CoO2 layer. Enhanced thermoelectric power S was also observed in the Ca-doped samples with the largest S as for x=0.2. The variation of S(T) could reflect the change of electronic correlation or the modification of local density of states and band structure near the Fermi energy. In addition, magnetic measurements show that the samples with x=0.0 exhibit abnormal and abrupt changes, revealing a possible thermally excited spin-state transition. It is found that the thermoelectric performance is obviously enhanced by the low Ca-doping.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.