Y_2O_3和BaCeO_3掺杂对YBa_2Cu_3O_(7-δ)多晶结构和超性质的影响（英文）  

Y_2O_3 AND BaCeO_3 DOPING INFLUENCE ON POLYCRYSTALLINE STRUCTURE AND SUPERCONDUCTING PROPERTIES OF YBa_2Cu_3O_(7-δ)

作　　者：张明发[1,2] 孙爱民[1,2] 马书懿[1,2] 王丹[1,2] 石盼盼[1,2] 

机构地区：[1]西北师范大学物理与电子工程学院,兰州730070 [2]甘肃省原子分子物理与功能材料重点实验室,兰州730070

出　　处：《低温物理学报》2015年第3期211-218,共8页Low Temperature Physical Letters

基　　金：supported by the college basic scientific research operation cost of Gansu province (the manufacture and characteristic research of the optical gas sensing film materials and the Y series superconducting materials)

摘　　要：本文采用固相反应方法制备了一系列YBa2Cu3O7-δ(Y123)+0.25molY2O3+x wt%BaCeO3(x=0.0,2.0,5.0,10.0and 20.0)多晶样品,通过X射线衍射法(XRD)和扫描电子显微镜(SEM)对Y2O3和BaCeO3的参杂的样品微观结构和超导转变温度进行系统的测量,发现Y2O3参杂到YBCO样品表面有球形或椭球形Y2Ba1Cu1O7-δ(Y211)粒子形成.依据SEM,XRD和电阻率测量,随着BaCeO3参杂量的增加,我们观察到样品的形貌变得越来越不均匀,所有样品的晶体结构有从正交相向四方相转变的趋势,超导转变温度呈金属状态到半导体状态转变的趋势,并伴有三步转变过程;同时也观察到了超导转变温度降低且转变宽度增加的现象,这些结果可以用氧分布的变化和缺陷的变化及氧缺陷来解释.A synthesis of polycrystalline YBa2Cu3O7-δ（Y123,YBCO）＋0.25 mol Y2O3＋x wt% BaCeO3（x=0.0,2.0,5.0,10.0and 20.0）superconductors have been done in air via a standard solid state reaction technique.The effects of Y2O3 and BaCeO3addition on the microstructure and the superconducting transition temperature were systematically investigated through X-Ray Diffraction（XRD）and Scanning Electron Microscope（SEM）techniques.It is find that Y2O3 was added to the YBCO,the samples have many Y211 formations and look like spherical or ellipsoidal shape.According to SEM,XRD and resistivity measurements,we observe that with increased of BaCeO3 concentration,the morphology becomes more and more inhomogeneous,all samples change the structure from orthorhombic to tetragonal and the normal state resistivity shows a change from metallic to semi-conducting behavior,and the samples of transition temperature appear to three steps transition,Meantime,the temperature of the samples transition decreases and transition width broadens.These results can be interpreted by the change of oxygen distribution and by the variation of defects,and oxygen decadency.

关 键 词：YBA2CU3O7-Δ超导体 BaCeO3添加 微观结构 超导电性 

分 类 号：TM26[一般工业技术—材料科学与工程] O611.3[电气工程—电工理论与新技术]