混合物理化学气相沉积法制备Al_2O_3衬底MgB_2薄膜性质的研究  

GROWTH AND PROPERTIES OF SUPERCONDUCTING MgB_2 THIN FILM FABRICATED ON Al_2O_3 SUBSTRATE BY HYBRID PHYSICAL CHEMICAL VAPOR DEPOSITION

作　　者：丁莉莉[1] 姚丹[1] 陈莉萍[1] 庄承钢[1] 张开诚[1] 陈晋平[1] 熊光成[1] 冯庆荣[1] 

机构地区：[1]北京大学物理学院

出　　处：《低温物理学报》2005年第A02期919-925,共7页Low Temperature Physical Letters

基　　金：北京大学物理学院研究项目;国家重点基金研究项目(BKBRSF-G19990646-02)~~

摘　　要：我们用混合物理化学气相沉积(Hybrid Physical-Chemical Vapor Deposition简称为HPCVD)法在Al2O3(00l)衬底上原位制备了MgB2超导薄膜样品.样品厚度约为1μm左右,最高的超导起始转变温度Tc(onset)=40.3K,转变宽度ΔT为0.3K.ρ50K=2.3μΩcm,剩余电阻比率RRR=R300K/R50K=10.样品的X射线衍射分析表明,MgB2薄膜具有较好的c轴取向,晶粒大小约200nm.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=7.6×106A/cm2,不同磁场下测得R^T曲线可以外推得到Hc2(0K)约10T.这些结果表明HPCVD技术在MgB2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 superconducting MgB2 thin films on Al2O3（001） substrate by using the hybrid physical chemical vapor deposition（HPCVD） technique. The thin films shows Tc（onset）=40. 3K with △T =0.3K, and have a thickness of about 1μm. The measurements of R～T curve shows that the film with a resistance of 2.3μΩcm at 50K and RRR～10. X-ray diffraction pattern indicates the film possess a c-ads-oriented crystal structure perpendicular to the substrate surface. We obtain high critical current densities（Jc） = 7. 6 × 10^6 A/cm^2 at 5K under self-field using Bean-Model calculating from the magnetic hysteresis measurements. According to the Resistance-Temperature curve under different magnetic field, we estimated Hc2 （0K）～10T. 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-光衍射图 SEM图 R^T曲线 M^H曲线 

分 类 号：O511.3[一般工业技术—材料科学与工程]