Effect of La-doping on growth and superconductivity of Bi-2212 crystals

作者：Jin H^*; Kotzler J

来源：Physica C-Superconductivity and Its Applications, 1999, 325(3-4): 153-158.

DOI：10.1016/S0921-4534(99)00457-8

• crystal growth
• Bi-2212
• substitution effects
• structure
• transition temperature

Single crystals of the layered superconductor Bi2Sr2(Ca1-xLax)Cu2O8+delta were successfully grown out by a self-flux method. Upon La-doping, the c-axis contracts but the structure remains stable up to the critical concentration x(c), above which the crystals contain the pure Bi-2(Sr,La)(2)CuO6 phase. The reduction of the superconducting transition temperature follows a linear relation, T-c(x)= T-c(0)(1 - x/x(c)), with x(c) = 0.3 being consistent with the structure data. This, and a comparison with literature data on Pr3+- (x(c) approximate to 0.65) and Y3+ -doping (x(c) = 1), indicate an intimate relation between structural and superconducting stability in the 2212 phase. Besides the widely discussed hole-filling effect, the structural instability due to the substitution of large La3+ for Ca2+ is considered to be another contribution to T-c suppression in this system.

• 出版日期1999-11-20
• 单位中国科学技术大学