The Transport Properties of Bi-Riched Bi 2 Sr 2 CuO 6+δ Single Crystal

As-grown superconducting Bi-riched Bi 2 Sr 2 CuO 6+δ single crystals have been grown by the traveling solvent floating zone technique. The superconducting transition temperature T c was about 6 K and the room temperature resistivity was about 2×10 −3 Ohm-cm. Transport properties, such as resistivity, magnetoresistance and Hall effect were measured from overdoped to underdoped samples annealed in inert atmosphere at 650°C. The transition temperature can be raised to 12 K after post annealing. The Hall measurement shows that the hole carrier density decrease after annealing. The temperature dependence of Hall angle is T 1.5 , not quadratic as observed for most high- T c superconducting oxides such as YBa 2 Cu 3 O 7 . The variation of onset T c with different external magnetic field is very different from high- T c superconductors. The in-plane conductivity shows the dependence of ln T and can be explained by weak localization theory.