摘要
本文提出了一种局域氧有序的限制通渗模型,从理论上计算出了TBa2Cu3O6+x高温超导体临界温度Tc与氧含量之间的关系曲线,与实验曲线符合得非常好.并对Tc~x实验曲线上出现的"台阶"现象进行了分析.随着x的增加出现了两种结构相变:四方相到正交相、正交(Ⅰ)相到正交(Ⅱ)相的转变.这些转变有逾渗机制.
In the present paper, a limited short-range-order-oxygen percolation model is proposed, thecurve of critical temperature To as a function of oxygen content theoretically is calculated in highTc superconductor YBa2Cu3O6+x system,and shows good agreement with the experimental curve. Andthe "plateaus"on the experimental curve Tc-x are analysed. With the increase of x two structuretransitions occu r: tetragonal-orthorhombio phase transition and orthorhombic (Ⅰ)-orthorhombic (Ⅱ)phase transition. There are Percolative mechanisms in those transitions.
基金
国家自然科学基金
关键词
氧化物超导体
临界温度
逾渗理论
high-Tc superconductor
phase transition temperature
percolation.