摘要
利用脉冲激光分子束外延技术(MBE)在LaAlO3(100)基片上依次沉积了La2/3Sr1/3MnO3(LSMO)、BaTiO3(BTO)和Bi4Ti3O12(BIT)薄膜。采用X射线衍射仪(XRD)、压电力显微镜(PFM)和铁电仪研究了复合薄膜的晶体结构、表面形貌、畴结构、单点压电响应信号以及电滞回线。结果表明所制BIT/BTO铁电复合薄膜沿c轴择优取向生长,其PFM相位曲线的畴翻转特征加之明显的振幅-电压蝴蝶曲线证实了该复合薄膜具有良好的铁电性;在外加8 V电压下BIT/BTO复合薄膜的剩余极化强度(2Pr)为(2.6±0.1)×10–6 C/cm2,而单层BIT和BTO铁电薄膜的2Pr仅为(1.1±0.1)×10–6 C/cm2和(0.3±0.1)×10–6 C/cm2,该现象与复合薄膜的界面效应以及晶体结构畸变有关。
Epitaxial La2/3Sr1/3MnO3（LSMO）, BaTiO3（BTO）, Bi4Ti3O12（BIT） were successively deposited on LaAIO3（100） substrate by pulsed laser molecular beam epitaxial technique （MBE）. Structure, surface morphology, domain structure, local switching spectroscopy and ferroelectric hysteresis loop of films were investigated by X-ray diffraction（XRD）, piezoelectric force microscopy （PFM） and ferroelectric instrument, respectively. The results indicate that prepared BIT/BTO ferroelectric composite films are preferential orientation along the c axis, and the PFM phase loop with the domain switching characteristic and amplitude-voltage butterfly loop demonstrate that the films possess good ferroelectric behavior. The remnant polarization（2Pr） of BIT/BTO composite film is （2.6±0.1）× 10-6 C/cm2 under applying voltage of 8 V, whereas the 2Pr of BIT film and BTO film are only （1.1±0.1）×10-6 C/cm2 and （0.3±0.1）×10-6 C/cm2, respectively. Such improvement of ferroelectric properties in composite film could be attributed to interface effect and crystal structure distortion.
出处
《电子元件与材料》
CAS
CSCD
北大核心
2014年第4期13-16,共4页
Electronic Components And Materials
基金
国家自然科学基金资助项目(No.61078057
No.51172183
No.51202195)
陕西省自然科学基金资助项目(No.2012JQ8013)
关键词
BIT
BTO铁电复合薄膜
分子束外延
剩余极化强度
矫顽场
振幅
电压蝴蝶曲线
畴翻转特征
BIT/BTO ferroelectric composite film
molecular beam epitaxial
remnant polarization
coercive field
amplitude-voltage butterfly loop
domain switching characteristic
