【摘要】 本文系统地研究了YBa_2-xSr_xCu₃O_7-σ中超导电性与物相以及结构变化之间的关系。发现当0<x≤1.25时,样品均具有单相的1-2-3正交结构,但其超导临界温度T_c并不随Sr的含量而单调变化。在x=1.0处,T_c出现一峰值。同时,超导临界温度与样品的晶体结构之间呈现出强烈的相关性:随着正交性的增强（即a,b间差值的增大）,T_c单调地上升。本文还就Sr原子对T_c的影响机制,以及物相、结构变化与超导电性之间的关联作了讨论。更多还原

【Abstract】 The relation between superconductivity and phase structure of YBa_2-xSr_xCu₃O_7-δ system has been studied systematically. It is found that when 0<x≤1.25, the samples all exhibit the 1-2-3 orthorhombic structure of single phase, but their superconducting critical temperatures do not change monotonously with Sr content. Meanwhile, superconducting critical-temperature shows dramatic dependence on the crystal structure of the samples: with the increase of the difference of a and b, T_c increases monotonously. The mechanism of the effect of Sr atom on T_c and superconductivity have also been discussed.更多还原