电子束蒸发在不同Ar气氛下外退火制备MgB_2超导薄膜  

SUPERCONDUCTING MgB_2 FILMS VIA EX-SITU ANNEALING UNDER DIFFERENT Ar PRESSURE PREPARED BY E-BEAM EVAPORATION

作　　者：吴克[1] 余增强[1] 张解东[1] 王守证[1] 聂瑞娟[1] 王福仁[1] 

机构地区：[1]北京大学物理学院

出　　处：《低温物理学报》2006年第3期212-218,共7页Low Temperature Physical Letters

摘　　要：制备高质量的MgB2薄膜是实现MgB2超导电子器件应用的前提和基础.我们用电子束蒸发B膜和Mg/B多层膜为前驱然后后退火的方法,分别在高温区(~900℃)和中温区(~750℃)成功获得了MgB2超导薄膜.改变退火的Ar气压条件,采用B膜前驱退火的样品Tc可达到38K以上,转变宽度0.3K.Mg/B多层膜的结果尽管Tc稍低(Tc^35K),但薄膜表面更加均匀,且避免了高温下Mg蒸汽污染的问题.对于两种前驱退火中观察到的完全不同的退火气压影响,我们认为是与其各自的超导成相过程相联系的,在此基础上我们对退火气压效应给出了自己的分析和解释,为今后进一步细致研究退火过程中的薄膜生长机制提供了参考.To fabricate high quality MgB2 thin films is fundamental for further applications of superconducting devices. With boron films and Mg/B multilayer prepared by E-beam evaporation as the precursors, we succeeded in growing MgB2 films through the post-annealing method. Adjusting the argon pressure during the annealing process, the transition temperature of annealed B films exceeds 38K with a transition width about 0.3K. Though the Tc of annealed Mg/B multilayer is depressed slightly （-35K）, the films＇ surface is more uniform and there is no pollution problem of Mg vapor. Significantly different effects of annealing pressure have been observed in these two approaches, we believed these are associated with their different phase formation processes. Some analyses have been proposed to explain the phenomenon, and these will provide a picture for further study of film growing mechanism during the annealing process.

关 键 词：MgB2薄膜 电子束蒸发 外退火 超导成相 

分 类 号：O484.1[理学—固体物理]