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采用溶胶-凝胶法和快速热处理工艺,在Pt(111)/Ti/SiO_2/Si(100)衬底上制备出Bi_4Ti_3O_(12)及其La~(3+)、Nd~(3+)掺杂系列铁电薄膜Bi3.5(La/Nd)_(0.5)Ti_3O_(12),并对其相组成、微观结构、铁电和介电性能进行了研究。X射线衍射谱和SEM综合显示,薄膜均匀、致密,呈随机取向的多晶钙钛矿结构。铁电和介电性能研究表明:其掺杂系列较未掺杂薄膜具有更优异的极化行为和矩形度(剩余极化强度Pr从9.35μC/cm2增至15.53和26.24μC/cm2)、更低的漏电流密度(从10-4 A/cm2降至10-6 A/cm2甚至10-9 A/cm2)和更高的介电常数,但同时介电损耗也逐渐增加(高频段时tanδ从0.02增至0.10和0.25)。
The Bi_4Ti_3O_ (12) and its La_ (3 +) and Nd_ (3 +) doping were prepared on the Pt (111) / Ti / SiO_2 / Si (100) substrate by sol-gel method and rapid thermal treatment (Bi3.5 (La / Nd) _ (0.5) Ti_3O_ (12)) thin films were synthesized and their phase composition, microstructure, ferroelectric and dielectric properties were investigated. X-ray diffraction spectrum and SEM analysis showed that the films were uniform and compact, with randomly oriented polycrystalline perovskite structure. The results of ferroelectric and dielectric properties show that the doped series have more excellent polarization behavior and squareness (the remanent polarization Pr increases from 9.35μC / cm2 to 15.53 and 26.24μC / cm2) than the undoped ones, and more Low leakage current density (10-4 A / cm2 down to 10-6 A / cm2 or even 10-9 A / cm2) and higher dielectric constant, but at the same time the dielectric loss is also gradually increased (high frequency band tanδ From 0.02 to 0.10 and 0.25).