用XRD和ACS测量研究Y_(1-x)Eu_xBa_2Cu_3O_(7-δ)超导体的应力钉扎机制  

XRD AND ACS STUDY ON STRESS-FIELD PINNING IN Y_(1-x) Eu_xBa_2Cu_3O_(7-δ) SUPERCONDUCTORS

作　　者：崔利杰[1] 段瑞飞[1] 李阳[1] 曹国辉[1] 马庆珠[1] 董成[2] 赵忠贤[2] 魏龙[3] 

机构地区：[1]北京科技大学材料物理系 [2]中国科学院高能物理所核分析技术开发实验室,北京100080 [3]中国科学院物理所国家超导实验室,北京100080

出　　处：《低温物理学报》2001年第2期81-88,共8页Low Temperature Physical Letters

基　　金：国家自然科学基金

摘　　要：利用X射线衍射 (XRD)和交流磁化率 (ACχ)方法系统地研究了Y1-xEuxBa2 Cu3O7-δ(x=0 .0～ 1.0 )超导体 ,研究发现Eu掺杂替代了Y晶位后引起了晶格失配 .这种晶格失配与电流密度有密切的联系 .对于不同掺杂成分样品 ,X射线衍射线形分析表明 ( 0 0 6)及 ( 0 0 7)衍射峰型随掺杂量变化 ,掺杂浓度在 30 %和 70 %附近时 ,半高宽 (FWHM)出现极大值 ,表明此时样品的晶格失配最大 .与此相对应 ,电流密度Js 也在此掺杂浓度范围内达到极大值 .我们在晶格失配应力场的钉扎模型下对实验现象进行了讨论 ,认为Y1-xEuxBa2 Cu3O7-δ超导体中由元素替代引起的晶格失配应力场是有效的钉扎中心 .We find Eu substituting Y or Y substituting Eu in Y 1-x Eu xBa 2Cu 3O 7-δ superconductors causes the lattice mismatch using the methods of X-Ray Diffraction(XRD) and Alternative Current Susceptibility(ACχ). There is a relatively connection between the lattice mismatch and the critical current density J\-s. The full widths at half maximum(FWHM) of (006) and (007) reflections in the experiment of XRD depend on Eu doping concentration. The maximum of FWHM occurs in the vicinity of x=0.3 and x=0.7, which indicates the lattice mismatch of samples reaches its maximum. Simultaneously, J\-s also reaches its maximum in the vicinity of x=0.3 and x=0.7. We discuss this experimental phenomenon using the model of stress-field pinning caused by the lattice mismatch. We consider that the lattice mismatch stress-field pinning caused by the lattice mismatch. We consider that the lattice mismatch stree-field, caused by the element substitute in Y 1-x Eu xBa 2Cu 3O 7-δ superconductors, is an effective pinning center.

关 键 词：X射线衍射 XRD 交流磁化率 ACS 临界电流密度 Y1-xEuxbA2Cu3O7-δ超导体 应力钉扎 晶格失配 

分 类 号：O511[理学—低温物理]