纳米粒子在不锈钢衬底MgB_2超导膜中的作用  

THE EFFECT OF NANO-PARTICLES IN SUPERCONDUCTING STAINLESS STEEL SUBSTRATES MgB_2 THIN FILMS

作　　者：王银博[1] 易声宇[1] 冯庆荣[1] 

机构地区：[1]北京大学物理学院和人工微结构与介观物理国家重点实验室,北京100871

出　　处：《低温物理学报》2008年第2期101-105,共5页Low Temperature Physical Letters

基　　金：国家自然科学基金(项目编号:50572001);国家"973"计划项目(项目编号:2006CD601004);国家基础科学人才培养基金(项目编号:J0630311)资助的课题~~

摘　　要：我们用混合物理化学气相沉积法(hybrid physical-chemical vapor deposition简称为HPCVD)以氩气为背景气体,在不锈钢衬底上于不同条件下制备了一批MgB2超导薄膜样品.用扫描电子显微镜获取了相关的SEM图像,并对膜的成分进行了能谱分析(EDX).当把不锈钢衬底MgB2超导薄膜弯曲不同角度之后,膜面上均出现了裂纹.裂纹的数量和宽度随弯曲的角度的增大而增加,但是膜始终紧紧地覆着在衬底上不脱落.因此我们可以说覆着在不锈钢衬底上的MgB2超导薄膜具有了很好的韧性.在膜中我们也发现有大量的数十纳米大小的晶粒.这个尺寸的纳米粒子的作用可以用来平衡MgB2膜内结构和表面晶粒的活性之间的相互作用.MgB2纳米粒子的存在是MgB2超导膜表现出韧性的关键角色.We have fabricated superconducting MgB2 thin film samples on stainless steel substrates by using hybrid physical-chemical vapor deposition （HPCVD） in pure argon atmosphere. Their SEM images and EDX analysis were performed. There were some cracks on the films surface appeared when they were bent at different angles. The numbers and the width of these cracks increased with the bending degree increasing but the films were still on the substrates firmly. This indicated that the superconducting MgB2 thin films have great ductility and adhesion to the stainless steel substrates. It was found many granules were about tens of nanometers wide in the films. This size can balance both the inner structure and the surface activity of the MgB2 crystal. The nano-particles of MgB2 should be an important reason for the ductility of the superconducting thin films.

关 键 词：混合物理化学气相沉积法(HPCVD) MGB2超导薄膜 不锈钢衬底 韧性 纳米粒子 

分 类 号：O484[理学—固体物理]