Upper critical field measurements using pulsed magnetic fields in Bi<sub>1.6</sub>Pb<sub>0.4</sub>Sr<sub>2</sub>Ca<sub>2</sub>Cu<sub>2+x</sub>O<sub>y</sub> (x=0.8, 1.2, 1.6)
Mao Xianglei; Liu Hongbao; Du Quan; Zhang Weijie; Mao Zhiqiang; Zhou Ling; Wang Yu; Zhang Yuheng; Mao Xianglei; Dept. of Phys., Univ. of Sci. & Technol. of China, Anhui, China; Liu Hongbao; Dept. of Phys., Univ. of Sci. & Technol. of China, Anhui, China; Du Quan; Dept. of Phys., Univ. of Sci. & Technol. of China, Anhui, China; Zhang Weijie; Dept. of Phys., Univ. of Sci. & Technol. of China, Anhui, China; Mao Zhiqiang; Dept. of Phys., Univ. of Sci. & Technol. of China, Anhui, China; Zhou Ling; Dept. of Phys., Univ. of Sci. & Technol. of China, Anhui, China; Wang Yu; Dept. of Phys., Univ. of Sci. & Technol. of China, Anhui, China; Zhang Yuheng; Dept. of Phys., Univ. of Sci. & Technol. of China, Anhui, China
Журнал:
Journal of Physics: Condensed Matter
Дата:
1989-04-24
Аннотация:
Upper critical magnetic fields of the Bi<sub>1.6</sub>Pb<sub>0.4</sub>Sr<sub>2</sub>Ca<sub>2</sub>Cu<sub>2+x</sub>O<sub>y</sub> system with x=0.8, 1.2, 1.6 were measured by a magnetoresistance method using a pulsed magnetic field. The H<sub>c2</sub>(0) are estimated to be 45.9, 218 and 64.9 T for x=0.8, 1.2, 1.6, respectively. H<sub>c1</sub>(T) for each composition was determined from magnetisation curves. The superconducting parameters xi , kappa and lambda were derived from experimental data. X-ray diffraction patterns show that there is no obvious change in structure. It is suggested that the coordination number of Cu strongly influences the superconductivity.
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