BaCuO2-δ含量和Sm/Gd比例对(SmGd)-Ba-Cu-O单畴样品超导性能和磁通钉扎机制的影响  

Effects of BaCuO_(2-δ) Addition and Sm/Gd Ratio on Superconducing Properties and Pinning Mechanism for (SmGd)-Ba-Cu-O Single-Domain Superconductors

作　　者：代建清[1] 赵忠贤[2] 

机构地区：[1]昆明理工大学,云南昆明650093 [2]中国科学院物理研究所超导国家重点实验室,北京100080

出　　处：《稀有金属材料与工程》2008年第5期753-757,共5页Rare Metal Materials and Engineering

基　　金：云南省中青年学术技术带头人后备人才培养项目(2006PY01-09)

摘　　要：采用热籽晶技术和"二步冷却"生长工艺,在空气中制备出了(SmGd)-Ba-Cu-O体系的单畴熔融织构样品,研究了BaCuO2-δ含量以及Sm/Gd比对超导性能和磁通钉扎机制的影响。研究表明,制备出的(SmGd)-Ba-Cu-O体系熔融织构样品没有宏观裂纹,77K下的冻结场呈中心对称的圆锥形;当BaCuO2-δ的加入量x=0.2时,样品的Tc和Jc都比较高,其超导性能达到最佳值,过高或过低BaCuO2-δ的含量都对超导性能不利;BaCuO2-δ的加入抑制了LRE-Ba的整体替代,使得超导基体中的组分波动具有更强的ΔTc钉扎;临界电流密度Jc和超导转变温度Tc都随着Sm/Gd比降低而增大,样品的临界电流密度都有非常明显的"鱼尾效应"。Single domain bulks of （SmGd）-Ba-Cu-O system have been successfully prepared under the ambient atmosphere via a two-step cooling method. The single peak in the trapped field distribution at 77 K indicates that the melt-grown bulk is single domain. The influences of BaCuO2-δ addition and Sm/Gd ratio on the superconducing properties and the pinning mechanism are investigated. The appropriate amount of BaCuO2-δ addition （x=0.2） can effectively improve the superconducting properties by suppressing the overall LRE-Ba substitution in the LRE123 matrix and hence improve the ΔTc pinning. In addition, both Jc and Tc increase with decreasing the Sm/Gd ratio, while all samples show a well-developed secondry peak effect.

关 键 词：(SmGd)-Ba-Cu-O 熔融织构 超导性能 磁通钉扎 

分 类 号：TM26[一般工业技术—材料科学与工程]