混合物理化学气相沉积法制备蓝宝石衬底外延MgB_2薄膜性质的研究  

GROWTH AND PROPERTIES OF SUPERCONDUCTING EPITAXIAL MgB_ 2 THIN FILM FABRICATED ON Al_ 2O_ 3 SUBSTRATE BY HYBRID PHYSICAL CHEMICAL VAPOR DEPOSITION

作　　者：丁莉莉[1] 陈莉萍[1] 李芬[1] 冯庆荣[1] 熊光成[1] 

机构地区：[1]北京大学物理学院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》2006年第2期107-111,共5页Low Temperature Physical Letters

基　　金：北京大学理学院和国家重点基金(项目编号:BKBRSFG1999064602)资助的课题.~~

摘　　要：我们用混合物理化学气相沉积(Hybridphysicalchemicalvapordeposition简称为HPCVD)法在αAl2O3(00l)衬底上原位制备了一批超导性能良好的外延MgB2超导薄膜样品.用10%浓度的乙硼烷(B2H6)氢气混合气作为原料,研究了不同条件对MgB2薄膜沉积速率的影响.在一定条件下制备了一批MgB2薄膜,厚度为200nm左右,样品的零电阻转变温度(Tc0)最高达到39K.X射线衍射分析的θ～2θ扫描表明,MgB2薄膜的晶粒都具有较好的C轴取向,对样品的(101)面Φ扫描结果显示MgB2薄膜晶格与衬底有很好的外延取向,取向关系为[1010]MgB2∥[1120]Al2O3.由毕恩模型计算求得在5K和零场条件下,样品的临界电流密度Jc=9.8×106A/cm2.这些结果表明HPCVD技术在MgB2外延薄膜原位制备方面有着很大的优势,从而有利于实现MgB2薄膜在电子器件方面的应用.We have fabricated several high quality epitaxial superconducting MgB2 thin films on αa-Al2O3 （001） substrate by using the hybrid physical chemical vapor deposition （HPCVD） technique. Using B2H6 precursor gas of 10% concentration, we studied the effect of different factors on the deposition rate of MgB2 thin films. Under definite conditions, we got a sae of superconducting MgB2 thin films with thickness of about 20Onm, and the Tc0 of the best sample is up to 39. 1 K. X-ray diffraction pattern indicates that the films possess a c-axis-oriented crystal structure perpendicular to the substrate surface. φscan of （ 101 ） MgB2 Reflections reveals that the MgB2 thin films is in-plane epitaxial but the lattice is rotated by 30°to match the hexagonal lattice of sapphire. We obtain high critical current densities（Jc） = 9.8 × 10^6 A/cm^2 at 5K under self-field using Bean-Model calculating from the magnetic hysteresis measurements. These indicate that the HPCVD technique is very promising for the in-situ fabrication of MgB2 thin films and MgB2 electronic devices.

关 键 词：MgB2薄膜 X射线衍射图 SEM图 R-T曲线 M-H曲线 

分 类 号：TM262[一般工业技术—材料科学与工程]