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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.
In this paper, a series of polycrystalline samples of YBa2Cu3O7-δ (Y123) + 0.25molY2O3 + xwt% BaCeO3 (x = 0.0,2.0,5.0,10.0and20.0) were prepared by solid-state reaction and characterized by X-ray diffraction The microstructure and superconducting transition temperature of Y2O3 and BaCeO3 samples were systematically investigated by scanning electron microscopy (SEM), and it was found that Y2CO3-Y2Ba1Cu1O7-δ (Y211) particles were formed on the surface of YBCO sample doped with Y2O3. SEM, XRD and resistivity measurement. With the increase of BaCeO3 content, we observed that the morphology of the samples became more and more uneven. The crystal structure of all the samples changed from quadrature phase to tetragonal phase. The superconductivity The transition temperature changes from the metal state to the semiconductor state, accompanied by the three-step transformation process. At the same time, the decrease of the superconducting transition temperature and the increase of the transition width are observed. These results can be obtained by the change of the oxygen distribution and the defects and the oxygen defects To explain.