YBa_2(Cu_(0.95)M_(0.05))_3O_(7-δ)的代换效应及其中子衍射研究  

SUBSTITUTION EFFECTS AND NEUTRON DIFFRACTION STUDY OF YBa_2(Cu_(0.95)M_(0.05))_3O_(7-δ)

作　　者：杨应昌[1] 查元勃 袁惟淳 杨继廉[2] 张百生[2] 周蕙明 丁永凡[2] 金兰[2] 叶春堂[2] 

机构地区：[1]北京大学物理系,北京100871 [2]中国原子能科学研究院,北东102413

出　　处：《物理学报》1990年第1期111-118,共8页Acta Physica Sinica

摘　　要：X射线衍射实验表明YBa_2(Cu_(0.95)M_(0.05))_3O_(7-δ)(M=Ti,V,Cr,Mn,Fe,Co,Ni,Cu和Zn)均为单相结构。Fe,Co,Ni和Zn对Cu的替代使超导临界温度T_c显著下降,而同样含量的Ti,V,Cr,Mn对Cu的替代并未对超导性能产生显著影响。并利用中子衍射分析了Ti,Mn,Fe和Co对Cu原子的取代,发现代换原子对Cu的两个晶位各自存在不同的择优占据,从而为分析不同晶位Cu在超导机制中的作用提供了依据。同时,本文研究了YBa_2·(Cu_(0.95)M_(0.05))_3O_(7-δ)的磁性,讨论了用3d金属离子代换Cu离子时对磁性的影响,以及磁性与超导性能之间的联系。YBa2(Cu_(0.95)M_(0.05))_3O_(7-δ) were identified as single phase with M = Ti, V, Cr, Mn, Fe, Co, N_1, Cu and Zn. Substitution of Fe, Co, Ni and Zn for Cu makes T_o, decrease significantly, while at the same content, no distructuve effect on T_c was observed in the replacement of Cu with Ti, V, Cr and Mn. The site occupation of Ti, Mn, Fe and Co ions has been investigated by using neutron diffraction technique, and strong site preference for these ions were observed. Based on these results, the two diffrent Cu sites and their relationship to the superconductivity in YBa_2Cu_3sO_(7-δ) are discussed. The substitution effect for copper on magnetic properties in YBa2(Cu_(0.95)M_(0.05))3O_(7-δ) and the correlation between magnetic and superconduc-tiviting properties are reported.

关 键 词：氧化物 代换效应 中子 衍射 超导体 

分 类 号：O511.1[理学—低温物理]