葡萄糖掺杂对MgB2钉扎机制的影响  

GLUCOSE DOPING IN l MgB_2 SUPERCONDUCTORS:PINNING MECHANISM

作　　者：王小峰[1] 李仪成[1] 崔雅静[1] 赵勇[1] 

机构地区：[1]磁浮技术与磁浮列车教育部重点实验室,西南交通大学超导与新能源研究开发中心,成都610031

出　　处：《低温物理学报》2012年第1期27-31,共5页Low Temperature Physical Letters

基　　金：国家自然科学基金(批准号:50588201,50872116,11004162);长江学者和创新团队发展计划项目(IRT0751);中国国家高科技项目(863计划批准号:2007AA03Z203);高等学校博士学科点专项科研基金(批准号:200806130023);中央高校基本科研业务费专项基金(批准号:SWJTU09ZT24,SWJTU09CX054)资助课题~~

摘　　要：本文通过磁性测量获得了葡萄糖掺杂MgB2块材样品的临界电流密度Jc,并利用集体钉扎模型分析了掺杂对其磁通钉扎机制的影响.研究发现,在纯样中δTc钉扎为主导钉扎机制;而在掺杂样品中,随着掺杂量的增加δl钉扎所占比重逐渐增大到90%.剩余电阻率的计算结果也验证了掺杂样品中的钉扎机制变化.我们推断δl钉扎主要是由碳对硼位掺杂引起的晶格无序造成的.In this paper, the critical current density Jc of pure and glucose-doped MgB2 bulk samples have been obtained by magnetic measurement. The effects of doping on the flux pinning mechanism have been analyzed according to the collective pinning model. It is found that the δTc pinning mechanism is mainly responsible for pure MgB2 sample while the δl pinning mechanism becomes dominant for glucose-doped samples. Further investigation revealed that in doping samples the δTc pinning also appeared, but with the increasing doping level the proportion of δTc pinning decreased, while the δl pinning gradually increased to 90%. The corrected residual rdsistivity results confirm the change of pinning mechanism in doped samples. It is demonstrated that the δl pinning is mainly caused by the lattice disorder effect arising from the substitution effects of carbon.

关 键 词：MGB2 磁通钉扎 葡萄糖掺杂 δl钉扎 (Tc钉扎 

分 类 号：TM26[一般工业技术—材料科学与工程]