偏轴磁控溅射法外延BiFeO_3薄膜的介电性能与阻变效应  

Resistive Switching Effect and Dielectric Property of Epitaxial BiFeO_3 Thin Films by Off-axis Magnetron Sputtering

作　　者：宋建民[1,2] 代秀红[1] 梁杰通 赵磊 周阳[1] 葛大勇[1] 孟旭东[3] 刘保亭[1] SONG Jian-Min;DAI Xiu-Hong;LIANG Jie-Tong~;ZHAO Leil;ZHOU Yang;GE Da-Yong;MENG Xu-Dong;LIU Bao-Tingt(College of Physics Science ＆ Technology,Hebei University,Baoding 071002,China;College of Science,Agriculture University of Hebei,B aoding 071001,China;College of Science,Hebei North University,Zhangjiakou 075000,China)

机构地区：[1]河北大学物理科学与技术学院,保定071002 [2]河北农业大学理学院,保定071001 [3]河北北方学院理学院,张家口075000

出　　处：《无机材料学报》2018年第9期1017-1021,共5页Journal of Inorganic Materials

基　　金：国家自然科学基金(11374086;11474174);河北省自然科学基金(E2014201188;E2014201063;A2018201168);河北省教育厅基金(2016058);河北农业大学理工基金(ZD20160614)~~

摘　　要：利用偏轴射频磁控溅射法,在(001)SrTiO_3(STO)单晶基片上制备了Pt/BiFeO_3/La_(0.5)Sr_(0.5)CoO_3/STO(Pt/BFO/LSCO/STO)异质结电容器。研究了BiFeO_3薄膜的结构和物理性能。原子力显微镜(AFM)和X射线衍射(XRD)分析表明:BFO薄膜结晶质量良好,且为单相(00l)外延钙钛矿结构。介电性能测试结果发现:在5 V驱动电压下,Pt/BFO/LSCO电容器呈现饱和的蝶形回线,调谐率和介电损耗分别为14.1%和0.19。此外,阻变机制研究表明:在0→5→0 V正向电压和0→–5→0 V负向电压下,阻变均为高阻向低阻转变规律,呈现为铁电二极管的阻变开关行为。通过I–V曲线拟合,得到0→5→0→–5 V时阻变机制为空间电荷限制电流陷阱能级的填充和脱陷,而–5→0 V时符合界面限制的F-N隧穿机制。The Pt/BiFeO3/La（0.5） Sr（0.5） CoO3/SrTiO3（Pt/BFO/LSCO/STO） heterostructures were fabricated on（001） SrTiO3 substrate by off-axis RF magnetron sputtering, on which epitaxial BiFeO3（BFO） thin films were suecessfully grown. The BFO thin film shows good crystal quality with（00 l） epitaxial growth as confirmed by the atomic force microscope（AFM） and X-ray diffraction（XRD）. Pt/BFO/LSCO capacitor exhibits a saturated butterfly loop with tuning rate of 14.1% and dielectric loss of 0.19 at 5 V driving voltage. Moreover, the resistance changes from high value to low value with positive voltage 0→5→0 V and negative voltage 0→–5→0 V, which displays switch behavior of ferroelectric diode resistance-change. Based on the I–V fitting curves, the resistance change mechanism fits the space charge limited current trap level when 0→5→0→–5 V and the interface limit F-N tunneling mechanism as –5→0 V, respectively.

关 键 词：铁酸铋薄膜 介电常数 阻变效应 导电机制 

分 类 号：O484[理学—固体物理]