Nanometer-scale Electrical Properties of Ferroelectric Organic Thin Films Investigated by Scanning Probe Microscopy

聚乙烯（Vinylidene fluorde/trifluoroethylene）的复合物的Ultarthin薄膜是由自旋涂层方法制备的，并通过随后的热退火。通过原子力显微镜（AFM）对电影的高分辨率成像，该图像由典型尺寸的宽度为100纳米，长度为100纳米。在添加中，内部精细结构还发现了颗粒内部。纳米尺度极化域的电气性质是由应用的高电场使用有条件的AFM坎蒂勒进行了调查。Furthermore，该领域大小对轮询条件的依赖性，如电压和时间也是调查的。结果表明，那些持久的极化层的存在被聚合物薄膜和底层表面之间的相互作用导致了，薄膜上表面潜力的局部变异被扫描Maxwell显微镜映射。“观察到的极化域上的潜力的极化显示，潜力的起源不是由轮询引起的，但一些电荷被注入或沉积的提示。最后，在最佳轮询条件下，有一个直径为30纳米的极化域在胶片上成功地发现了一个厚度为30纳米。由于此记录大小对应于230 Gbit/in的记录密度为230 Gbit/in，因此该技术被提议用于超高密度数据存储。

Ultarthin films of copolymers of poly (vinylidene fluorde/trifluoroethylene) on a conduting substrate were prepared by spin-coating method and by the following thermal anealing. High-resolution imaging of the films by atomic force microscopy (AFM) revealed that the films consisted of rod-like grains of which the typical dimensions were 100 nm in width and 100 nm in length. In addition, internal fine structures inside the grains were also found.Electrical properties of nanometer-scale polarized domains which were formed by applying high electric field using a conductive AFM cantilever were investigated. Furthermore, the dependence of the size of the domains on the poling condition such as voltage and time was also investigated. The results indicated the existence of a persistent polarized layer which was caused by the interaction between the polymer film and the substrate surface.Local variation in surface potential on the films was mapped by Scanning Maxwell Microscopy. The observed polarity of the potential on the polarlized domains showed that the origin of the potential was not the dipole oriented by the poling but some charges injected or deposited by the tip.Finally, in the optimum poling condition the polarized domains with a diameter of 30 nm were successfully obtained on the film with a thickness of 30 nm. Since this recording size corresponds to a recording density of 230 Gbit/inィイD12ィエD1, the technique is promising for an ultrahigh density data storage.