| 摘 要： | We report a reproducible approach in preparing high-quality overdoped Bi_2Sr_2CaCu_2O_(8+δ)(Bi2212) single crystals by annealing Bi2212 crystals in high oxygen pressure followed by a fast quenching.In this way,high-quality overdoped and heavily overdoped Bi2212 single crystals are obtained by controlling the annealing oxygen pressure.We find that,beyond a limit of oxygen pressure that can achieve most heavily overdoped Bi2212 with a T_c ~63K,the annealed Bi2212 begins to decompose.This accounts for the existence of the hole-doping limit and thus the T_c limit in the heavily overdoped region of Bi2212 by the oxygen annealing process.These results provide a reliable way in preparing high-quality overdoped and heavily overdoped Bi2212 crystals that are important for studies of the physical properties,electronic structure and superconductivity mechanism of the cuprate superconductors.
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