MgB_2/Fe带材J_c的各向异性及MgB_2芯织构和成分不均一性的研究  

STUDY ON THE ANISOTROPY OF CRITICAL CURRENT DENSITIES,TEXTURE AND PHASE INHOMOGENEITY IN MgB_2/Fe TAPES

作　　者：索红莉[1] 王颖[1] 马红霞[1] 刘丹敏[1] 周美玲[1] Paola Lezza Rene Flukiger 

机构地区：[1]国家教育部功能材料重点实验室,北京工业大学材料学院北京100022 [2]University of Geneva D.P.M.C,24 Quai Ernest-Ansermet 1211 Geneva

出　　处：《低温物理学报》2005年第A01期738-744,共7页Low Temperature Physical Letters

基　　金：国家教委全国百篇优秀博士论文专项资金(项目编号:200331)~~

摘　　要：本文研究了在不同磁场方向和温度下非原位Fe包套MgB2单芯带Jc的各向异性,通过对各种工艺条件下带材中MgB2芯的X-ray衍射图进行拟合分析和计算,比较了MgB2芯在Fe-MgB2界面和中心处的织构度和成份不均一性.研究发现带材Jc的各向异性受初始粉末颗粒尺寸的影响.由于受套管材料强度和形变加工工艺的影响,MgB2芯在Fe-MgB2界面处比在中心处有较强的织构.在MgB2-Fe的界面处,700℃淬火样品的X-ray衍射图中发现了由中间相Fe23B6生成的金属间化合物Fe2B.另外还研究了MgB4和MgO等主要杂质相的形成原因.The anisotropy of the critical current density of ex-situ MgB2/Fe sheathed monofilamentary tapes has been measured at various magnetic fields and temperatures. The inhomogeneous distributions of the phases between the core and the MgB2/Fe interface in the MgB2 filaments produced through various process were calculated by the XRD refinements. The results show that the anisotropy of the critical current density was influenced by the starting particle sizes of MgB2 powder. It was found that the degree of texturing of the filaments at the interface was better than in the centre of the filaments due to the influence of the hardness of the sheath material and the deformation craftwork. Tapes annealed at 700℃ revealed the presence of the Fe2B phase formed by the decomposition of Fe23B6. In addition, some impure phases such as MgB4 and MgO were found in the MgB2 filaments. The relationship between anisotropy of the critical current density and the texture in the filament was discussed.

关 键 词：非原位MgB2/Fe超导带 X—ray衍射拟合分析 临界电流密度Jc 各向异性 

分 类 号：O511.3[一般工业技术—材料科学与工程]