摘要
本文报道通过对YBa_2Cu_(1-x)Co_x(Cu_(1-y)Zn_y)_2O_x(0≤x,y≤0.1)体系晶体结构、氧含量、正常态电阻-温度关系、Hall效应以及超导临界温度等的综合测量,发现随着Co和Zn含量的增加,体系经历了从正交结构的超导金属向四方结构的非超导半导体的转变,超导临界温度T_c和载流子浓度n_h均迅速下降,Co和Zn的同时掺杂效应不是两者分别掺杂效应的简单叠加,而是存在着强烈的相关性。实验结果表明,Cu-O链与Cu-O平面之间的相互耦合对体系的电子输运性质和超导电性有着重大影响。还对载流子特性以及T_c与n_h之间的关系作了初步探讨。
The crystal structure, oxygen content, resistance, Hall effect and superconducting crkical temperature of YBa2Cu1-xCox (Cu1-yZn_y)2O_x system (0≤x, y≤0.1) have been studied. It is found that with increase of Co and Zn contents, the transformation from superconducting metal with orthorhombic structure to non-superconducting semiconductor with tetragonal structure occurs. At the same time, the T_c and the carrier density n_k decrease sharply. The effects with Co and Zn doping simultaneously are not simply additive. With increase of Co and Zn concentrations, there is a strong coorelation between Co doping on Cu(l) and Zn on Cu (2) sites. The experimental results show that the coupling between Cu-O planes and Cu-O chains gives much influence on the electronic transport properties in normal states and superconductivity. The characteristics of the hole carriers and its dependence on T_c in 123 phase compounds are also dicussed.
出处
《物理学报》
SCIE
EI
CAS
CSCD
北大核心
1991年第5期807-814,共8页
Acta Physica Sinica
基金
国家自然科学基金
