PbTiO3/PbZr0.3Ti0.7O3/PbTiO3夹心结构铁电薄膜子晶层的优化  

Optimization of seed layer of PbTiO_3/PbZr_(0.3)Ti_(0.7)O_3/PbTiO_3 sandwich structure ferroelectric thin film

作　　者：王龙海[1] 于军[1] 王耘波[1] 高峻雄[1] 赵素玲[2] 

机构地区：[1]华中科技大学电子科学与技术系,武汉430074 [2]武汉理工大学材料研究与测试中心,武汉430070

出　　处：《物理学报》2008年第2期1207-1213,共7页Acta Physica Sinica

基　　金：国家自然科学基金重大研究计划(批准号:90407023)资助的课题.~~

摘　　要：用Sol-Gel法制备了Pb(1+x)TiO3/PbZr0·3Ti0·7O3/Pb(1+x)TiO3(PT/PZT/PT)夹心结构及PZT铁电薄膜,为了获得高质量的PT/PZT/PT夹心结构铁电薄膜,使用不同过量Pb配比(x)的PbTiO3(PT)层进行制备,以获得优化的PT子晶层.X射线衍射和原子力显微镜分析结果表明PT层中过量Pb配比(x)对薄膜的微结构影响很大,只有PT层中Pb过量配比x=0·10—0·15的薄膜为表面晶粒大小均匀致密的纯钙钛矿结构.X射线电子能谱对薄膜微区进行元素成分分析表明,对x=0·00的薄膜,在表面和界面处Pb明显的缺乏;而x=0·20时的薄膜,Pb则明显的过量.薄膜的铁电性能、疲劳特性和漏电流特性等电学性能与PT层中过量Pb配比(x)没有明显的变化趋势,但与薄膜的结晶性能密切相关.结晶性能较好的薄膜,其电学性能也较好.说明PT层中过量Pb配比(x)是通过影响PT子晶层自身的结晶,而影响整个薄膜的结晶行为,并进一步影响到整个薄膜的电学性能.因此,在其他工艺参数都相同时,PT层中合适的过量Pb配比应为x=0·10—0·15.优化的子晶层不仅能获得结晶性能较好的薄膜,而且薄膜的电学性能也好.The PT/PZT/PT and PZT thin films were prepared by sol-gel method. Different Pb content （x） （x = 0, 0.05, 0.10, 0.15, 0.20） were added in excess to the PT precursor to optimize PT seed layer. The XRD and AFM results show that the crystalline phase and microstructure of the films were greatly affected by the excess Pb content （ x ） in PT layers. The pure perovskite structure PT/PZT/PT films with dense, void-free and uniform fine grain size were obtained for the proper choice of excess Pb content （x = 0.10-0.15）. EDX results showed that, in the interlayer and surface regions, the Pb deficiently and Pb abandance are obvious for the samples of x = 0 and x = 0.2, respectively. The ferroelectric, fatigue and leakage current properties of the films are not obviously relate to the change of excess Pb content （ x）, but correlate obviously with the crystalline behavior of PT layers. A well-saturated hysteresis loop with high remnant polarization, excellent fatigue properties and low leakage curremt were obtained for the films of excess Pb content x = 0.10 and 0.15. The excess Pb content （x） in PT layers affects the crystallization of PT layer, which will act as a nucleation site or seeding layer for PZT films and affect the perovskite phase formation of the PZT films. The optimized seed layer with excess Pb content x = 0.10-0.15 improves not only the microstructure, but also the electric properties.

关 键 词：PT/PZT/PT 夹心结构 子晶 铁电薄膜 

分 类 号：O484[理学—固体物理]