热处理对MgB_2超导体超导电性和显微结构的影响  

EFFECT OF HEAT TREATMENT ON THE SUPERCONDUCTIVITY AND MICROSTRUCTURE OF MgB_2

作　　者：周杰俤[1] 杨烨[1] 潘熙锋[1] 张勇[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研究开发中心

出　　处：《低温物理学报》2009年第1期16-19,共4页Low Temperature Physical Letters

基　　金：国家自然科学基金(项目编号:50372052;50588201);国家重大基础研究项目(973)(项目编号:2007CB616906);长江学者和创新团队发展计划项目(IRT0751);西南交通大学青年教师科研起步项目(2007Q014)资助的课题~~

摘　　要：采用固相反应法常压下制备MgB2超导块材,研究两种不同的热处理工艺(淬火、预热)对MgB2超导电性和显微结构的影响.结果显示淬火有助于细化晶粒,提高样品的临界电流密度;预热在一定程度上提高MgB2样品的致密度和磁通钉扎力,其中随炉升温600℃预热1h再升至750℃保温0.5h后淬火的样品自场Jc达到0.586MA/cm2,不可逆场超过7T,20K下在0.8T达到最大钉扎力Fpmax.Prepared the MgB2 with the method of solid reaction, we investigate the effect of two different heat treatment techniques-quenching and preheating on the MgB2 superconductivity. It is revealed that quenching is beneficial to diminish the size of MgB2 grain and improve the critical current density. To a certain extent,preheating can increase the density and enhance the flux pinning. Sintering with temperature increasing to 750 ℃, preheating at 600 ℃ for one hour, heated halfhour at 750℃, then quench, the Jc reaches 0.586 MA/cm^2 at 10 K and self-field,the irrecersibility filed exceed 7T, the maximum volume pinning force is up to 0.8 T at 20K.

关 键 词：MGB2 临界电流密度 磁通钉扎 热处理 

分 类 号：TM26[一般工业技术—材料科学与工程] TG161[电气工程—电工理论与新技术]