有机铁电P(VDF-TrFE)膜的铁电开关特性  

The local ferroelectric switching process in P(VDF-TrFE) films

作　　者：朱国栋[1] 徐敬[2] 曾志刚[1] 张莉[1] 

机构地区：[1]复旦大学材料科学系,上海200433 [2]同济大学物理系,上海200092

出　　处：《材料研究学报》2006年第6期597-601,共5页Chinese Journal of Materials Research

摘　　要：借助原子力显微镜优异的空间分辨能力和微观压电铁电测定技术,研究了有机铁电P(VDF-TrFE)膜的微观铁电开关特性．结果表明,当激励电压的峰值高于材料矫顽电压时,观测到双峰振动现象,双峰振动的出现源自于铁电开关过程；当激励电压幅值略高于材料矫顽电压时,探测到振动双峰的发展过程和局域蝴蝶洄线的不对称生长,蝴蝶洄线左翼的生长速度明显滞后于右翼．当极化时间足够长时,两翼的生长达到饱和,呈现出对称结构．电极结构的不对称性(金、铝电极)导致陷阱电荷注入铁电膜内部的速率不同,从而产生不对称的蝴蝶洄线生长过程．空间电荷在有机聚合物铁电性形成过程中有重要的贡献．Based on the measuring technique of local （or microscopic） piezoelectricity and ferroelectricity and the excellent resolution of atomic force microscope, the local ferroele,ctric switching process in P（VDF-TrFE） films was studied. The local dual-peak vibrations on the surface of P（VDF-TrFE） films, induced by an alternating electric field with its amplitude higher than the coercive electric field of films were reparted, and such dual-peak vibrations were caused by ferroelectric switching process. The buildup of these dual-peak vibrations was observed, and the asymmetric development of local butterfly loops was also obtained. It is indicated that the asymmetric structure between the top Au and the bottom AI electrodes results in the different rates at which trapped charges are injected into ferroelectric films, and furthermore results in the asymmetric growth of local butterfly loops. It is proved that the contribution of trapped charges to the ferroelectric property in polymers.

关 键 词：有机高分子材料 P(VDF-TrFE) 铁电 原子力显微镜 电极效应 

分 类 号：O484[理学—固体物理] O482[理学—物理]