Crystallinity and transport properties in Bi<sub>2</sub>Sr<sub>2</sub>Ca<sub>1-x</sub>Pr<sub>x</sub>Cu<sub>2</sub>O<sub>y</sub> single crystals
S Y Li; Q Cao; Z Sun; X H Chen; L Z Cao; S Y Li; Structure Research Laboratory, Department of Physics, University of Science and Technology of China, Hefei, Anhui 230026, People's Republic of China; Q Cao; Structure Research Laboratory, Department of Physics, University of Science and Technology of China, Hefei, Anhui 230026, People's Republic of China; Z Sun; Structure Research Laboratory, Department of Physics, University of Science and Technology of China, Hefei, Anhui 230026, People's Republic of China; X H Chen; Structure Research Laboratory, Department of Physics, University of Science and Technology of China, Hefei, Anhui 230026, People's Republic of China; L Z Cao; Structure Research Laboratory, Department of Physics, University of Science and Technology of China, Hefei, Anhui 230026, People's Republic of China
Журнал:
Superconductor Science and Technology
Дата:
2000-12-01
Аннотация:
Bi<sub>2</sub>Sr<sub>2</sub>Ca<sub>1-x</sub>Pr<sub>x</sub>Cu<sub>2</sub>O<sub>y</sub> (x ranging from 0 to 0.5) single crystals have been grown by a self-flux method from Bi-rich melts. The crystals obtained manifest slim and plate-like shapes. The crystallinity is studied by x-ray diffraction. The x-ray θ-scanning rocking curve shows that the slim crystal has perfect crystal structure while the plate-like crystal is mosaic along the c-axis. The in-plane resistivity ρ<sub>ab</sub>(T) has been measured for crystals with different Pr doping levels. T<sub>c</sub> is suppressed gradually upon doping while the residual resistivity increases strongly. A superconductor-insulator transition is observed which is attributed to the tetragonal-orthorhombic phase transition when the Pr content reaches about 0.5. The effect of oxygen doping on in-plane resistivity ρ<sub>ab</sub>(T) is also studied for x = 0.22 and 0.40 crystals.
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