混合物理化学气相沉积法(HPCVD)制备的MgB_2超导厚膜样品的成分分析  

THE STUDY ON COMPONENT FOR MgB_2 THICK FILM PREPARED BY HPCVD

作　　者：贾璋[1] 郭蕙璞[1] 吕莹[1] 王新峰[1] 陈晋平[1] 徐军[1] 王晓楠[1] 朱萌[1] 冯庆荣[1] 

机构地区：[1]北京大学物理学系和国家人工微结构和界观物理重点实验室,北京100871

出　　处：《低温物理学报》2005年第1期46-53,共8页Low Temperature Physical Letters

基　　金：国家超导中心 (项目编号 :G19990 6 4 6 0 2 );北京大学"挑战杯"基金和校长基金资助的课题 .~~

摘　　要：本文介绍了基于混合物理化学气相沉积法 (HPCVD) ,以B2 H6 为硼源 ,在 (0 0 0l)取向的Al2 O3单晶衬底上 ,制备了MgB2 超导体厚膜样品 .该样品平均厚度约为 4 0 μm .其Tc(onset) =39K ,Tc(0 ) =37.2K .X光衍射图显示该膜沿 (10 1)方向生长 ,具有少量Mg和MgO杂相 .SEM图像、X射线能量损失谱以及背散射电子衍射图证实了这两种杂相的存在 ,并显示该样品成分富镁 .样品表面的镁与空气接触形成MgO膜 ,在一定程度上阻止了MgB2 样品进一步被氧化 .对于MgB2 厚膜成膜过程及反应机理 ,我们提出了一种新的推断 .Superconducting MgB\-2 thick film have been prepared by HPCVD method on Al\-2O\-3 (0001) substrate by using B\-2H\-6 and Magnesium ingot as the raw materials reacted from 730 to 830℃ for 40 minutes under 20 to 30 KPa. Its thickness is about 40μm. The MgB\-2 thick film shows T\-c (onset)=39.0K, T\-c (0)=37.2K. X ray diffraction pattern shows that the film grown along (101) direction with small amount impurities of Mg and MgO. SEM and EDX indicated that these impurities existed indeed and was rich Mg. The film of MgO was formed on the surface of the MgB\-2 thick film to protect the oxidation for the sample further. We presented a new mechanism of the formation of the thick film.

关 键 词：MgB2超导膜 SEM图 EDX X射线能谱 混合物理化学气相沉积法 

分 类 号：O511[理学—低温物理]