The carrier characteristics of single phase superconducting oxides (Bi, Pb)<sub>2</sub>Sr<sub>2</sub>Ca<sub>2</sub>Cu<sub>3</sub>O<sub>y</sub> under different heat treatments
Zhenhui He; Yiping Sun; Jian Sha; Huaqing Ying; Xiangai Chen; Xianhui Chen; Jianyi Jiang; Shunxi Wang; Jiaju Du; Liezhao Cao; Qirui Zhang; Zhenhui He; Dept. of Phys., Univ. of Sci. & Technol. of China, Hefei, China; Yiping Sun; Dept. of Phys., Univ. of Sci. & Technol. of China, Hefei, China; Jian Sha; Dept. of Phys., Univ. of Sci. & Technol. of China, Hefei, China; Huaqing Ying; Dept. of Phys., Univ. of Sci. & Technol. of China, Hefei, China; Xiangai Chen; Dept. of Phys., Univ. of Sci. & Technol. of China, Hefei, China; Xianhui Chen; Dept. of Phys., Univ. of Sci. & Technol. of China, Hefei, China; Jianyi Jiang; Dept. of Phys., Univ. of Sci. & Technol. of China, Hefei, China; Shunxi Wang; Dept. of Phys., Univ. of Sci. & Technol. of China, Hefei, China; Jiaju Du; Dept. of Phys., Univ. of Sci. & Technol. of China, Hefei, China; Liezhao Cao; Dept. of Phys., Univ. of Sci. & Technol. of China, Hefei, China; Qirui Zhang; Dept. of Phys., Univ. of Sci. & Technol. of China, Hefei, China
Журнал:
Superconductor Science and Technology
Дата:
1991-01-01
Аннотация:
Single phase samples (Bi, Pb)<sub>2</sub>Sr<sub>2</sub>Ca<sub>2</sub>Cu<sub>3</sub>O<sub>y</sub> have been prepared under different heat treatments. The midpoint transition temperature (Tc) is determined by both AC susceptibility and resistance measurement. The resistance-temperature coefficient is found changed from positive to negative when the sample is fast cooled. The Hall coefficient measurement shows that Tc increases monotonically with the effective carrier concentration (n<sub>H</sub>) and that n<sub>H</sub> increases with temperature linearly. The authors draw the conclusion that the reduction of the carrier concentration is caused not by the reduction of the oxygen content, but by the weak localization of the carriers which is unfavorable to High T<sub>c</sub>.
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