掺Mn拓扑绝缘体Bi_2Se_3薄膜的制备及其电磁特性研究  

Study of preparation and electromagnetic properties of Mn-doped Bi_2Se_3 thin films

作　　者：杜洪洋[1] 徐伟[1] 宋玲玲[1] 仇怀利[1] 李中军[1] 黄荣俊 DU Hongyang;XU Wei;SONG Lingling;QIU Huaili;LI Zhongjun;HUANG Rongjun(School of Electronic Science and Applied Physics,Hefei University of Technology,Hefei 230009,China)

机构地区：[1]合肥工业大学电子科学与应用物理学院,安徽合肥230009

出　　处：《合肥工业大学学报（自然科学版）》2018年第1期60-63,共4页Journal of Hefei University of Technology：Natural Science

基　　金：国家自然科学基金资助项目(21503061);中央高校基本科研业务费专项资金资助项目(JZ2015HGXJ0184;JZ2016HGBZ1046);国家大学生创新实验资助项目(201510359035)

摘　　要：文章利用分子束外延(molecular beam epitaxy,MBE)法在蓝宝石衬底上制备拓扑绝缘体Bi_2Se_3和掺杂Mn的拓扑绝缘体Bi_2Se_3的异质结薄膜。利用反射高能电子衍射仪(reflection high-energy electron diffraction,RHEED)和X射线衍射仪(X-ray diffraction,XRD)对不同条件制备的样品晶相进行分析,获得最优的制备参数,主要包括衬底温度为390℃、Bi和Se的流量比为1∶10以及Mn流量对应的温度为590℃;利用综合物性测量系统(physical property measurement system,PPMS)测量了样品的温度电阻、磁电阻和霍尔电阻。测量结果表明,与纯Bi_2Se_3薄膜相比,Bi_2Se_3和掺杂Mn的Bi_2Se_3构成的异质结薄膜的电阻随温度的升高表现出金属性-绝缘性的转变和更强的磁阻特性,而且由于异质层间的近邻效应导致异质薄膜表现出p型导电特性。In this paper,the hetero-structural thin films of Bi 2Se 3 and Mn-doped Bi 2Se 3 were prepared on sapphire substrate by molecular beam epitaxy(MBE)method.The analyses of the crystalline phase were performed based on the reflection high-energy electron diffraction(RHEED)and X-ray diffraction(XRD)for the thin films prepared at different conditions.The optimal preparation parameters are obtained as follows:the substrate temperature is 390℃,the flow ratio of Bi and Se is 1∶10 and the cell temperature for Mn is 590℃.The temperature-dependent resistance,Hall resistance and magnetic resistance of the samples were measured by using the physical property measurement system(PPMS).The results indicate that compared with the Bi 2Se 3 thin film,the resistance of the hetero-structural thin film of Bi 2Se 3 and Mn-doped Bi 2Se 3 shows a transition from metallic to insulating characters and stronger magnetoresistive properties with the increase of the temperature.Moreover,this hetero-structural thin film exhibits p-type conducting characteristic due to the proximate interaction.

关 键 词：分子束外延(MBE) BI 2Se 3异质薄膜 霍尔电阻 磁电阻 

分 类 号：O484.1[理学—固体物理]