基于扫描探针显微术研究Pb(Zr,Ti)O3铁电薄膜的电学性质
Study of Electrical Properties of Pb(Zr,Ti)O3 Ferroelectric Thin Film by Scanning Probe Microscopy
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摘要: 首先利用脉冲激光沉积技术在(001)取向的SrTiO3基片上外延生长了SrRuO3底电极和PbZr0.20Ti0.80O3(PZT)薄膜,然后利用扫描探针显微镜的压电响应模式(PFM)和导电测试模式(C-AFM)表征了PbZr0.20Ti0.80O3 /SrRuO3/ SrTiO3异质结薄膜纳米尺度的电学性质.以镀铂探针为上电极,利用压电响应模式获得了复合薄膜纳米尺度的压电位移-电压蝶形曲线和压电相位-电压滞后曲线,表明样品具有良好的铁电性.薄膜纳米尺度下的I-V测试结果表明经+10 V电压极化后的样品,其I-V曲线在矫顽场附近出现峰值,与宏观I-V测试结果类似.导电原子力和压电力测试结果证明C-AFM可以检测到PZT薄膜样品的瞬时极化反转电流并进行成像.Abstract: Pulsed laser deposition (PLD)technology was used to prepare SrRuO3 bottom electrode and epitaxial PbZr0.20Ti0.80O3 (PZT)films on the substrate of SrTiO3.Then,the nano-scale electrical properties of the thin film were studied by the multimode (PFM and C-AFM)scanning probe microscopy.The nano-scale piezoelectric displacement-electric field butterfly loop and the phase-electric field hysteresis loop obtained by using a conductive probe as the top electrode demonstrate that the films possessed good ferroelectric behavior.It is demonstrated that the nano-scale I-V curve of the sample polarized by +10 V voltage showed peak performance near the coercive electric field,and this result agreed well with the macroscopic I-V characteristics.The results made by the conductive atomic force microscopy and piezoresponse force microscopy suggested that the conductive atomic force microscopy could be used to detect and image the switching current of the PZT thin film.