稀土元素Ce/Eu共掺杂对Bi-2201相微结构和超导电性的影响  

THE EFFECT OF Ce/Eu CO-DOPING ON THE MICROSTRUCTURE AND SUPERCONDUCTIVITY IN THE Bi-2201 SYSTEM

作　　者：贾旭[1] 张建武[1] 郑保忠[1] 浦其荣[1] 

机构地区：[1]中国科学技术大学物理系,合肥230026

出　　处：《低温物理学报》2006年第4期368-372,共5页Low Temperature Physical Letters

基　　金：教育部留学回国人员启动基金(2004)资助的课题.~~

摘　　要：我们采用传统固相反应法成功制备了系列多晶样品Bi_(1.6)Pb_(0.4)Sr_(2-x)(Ce_(1-y)Eu_y)_xCuO_z(x=0.1,0.2;0≤y≤1),并且用XRD和电阻率分别对其晶体结构和输运性质进行了研究.XRD结果表明,当Ce/Eu共掺杂量x=0.1时,样品成单相,当x=0.2时,会有杂相出现;随着Eu掺杂量的增加及相应Ce掺杂量的减少,样品的晶胞参数a,b稍有增大,晶胞参数c则显著增大;电阻率测量表明,随着Eu掺杂量的增加,样品的超导转变温度Tocnset可以提高到21K,Ce掺杂对超导电性有一定的抑制作用,而Eu掺杂却能够改善超导电性,其中Tconset随Ce/Eu掺杂量的变化可以用电荷转移模型进行合理解释.Polycrystalline samples Bi1.6 Pb0.4 Sr2-x （ Ce1-y Euy ）, CuOx （ x = 0. 1, 0. 2; 0 ≤ y ≤ 1 ） were successfully synthesized by conventional solid-state reaction method. The crystal structure and transport properties were investigated by means of X-ray diffraction （XRD） and resistivity, respectively. The XRD results indicate that the samples with Ce/Eu co-doping content x = 0.1 are single phases, and begin to become impurity phases when x = 0.2. It is also found that, with increasing Eu doping content and correspondingly decreasing Ce doping content, the lattice parameters a and b increase slightly while the parameter c increases obviously. The resistivity results show that the Tc^onset can be increased up to 21K with the increase of Eu doping content y （0 ≤ y ≤ 1 ） ; the Ce doping suppresses the superconductivity strongly, whereas the Eu doping can improve the superconductivity. The variation of Tc^onset with the Ce/Eu doping content can be well interpreted by the charge transfer effect.

关 键 词：Bi2201 超导电性 输运性质 微结构 

分 类 号：O511[理学—低温物理]