Near Field Enhanced Raman Spectroscopy - Applications to Ferroelectric Thin Films

这项探索性研究（SGER）小额赠款奖将支持一个研究近场增强显微拉曼光谱在铁电薄膜中的应用的项目。 显微拉曼光谱已被证明是材料表征的有用工具。 然而，在绝缘衬底上生长的透明铁电薄膜中，拉曼信号下降到不可检测的水平。 在某些材料中，可以通过使用表面增强拉曼散射效应（Sers）来增强拉曼信号。 尝试将在感兴趣的薄铁电薄膜中通过在表面、衬底界面或大部分膜内引入金属（Au）纳米颗粒来创建Sers条件。 第二种方法将采用镀金的原子力显微镜（AFM）尖端作为放置在透明基板背面的单个金属颗粒。 这第二种方法也将被探索作为一种方法来绘制出，在纳米尺度上，扩展铁电薄膜的属性。铁电材料在许多技术应用中发挥着重要作用。 下一代先进和紧凑的集成电子器件将需要新型复杂的电子陶瓷和其他光电材料的薄膜。 材料加工和薄膜制造技术的最新发展使得可获得适用于这些应用的高质量薄膜。 铁电体是一类提供广泛有用特性的电瓷，可用于开发设备，如智能传感器和结构，抗辐射非易失性计算机存储器和热释电探测器。 这些设备的成功实施需要具有明确属性和设备品质因数的材料。 显微拉曼光谱已成为一种优秀的非破坏性工具，通过研究尺寸，应力/应变，温度，压力和电场对动态散射行为的影响，进行全面的材料表征。 为了从薄膜获得可测量强度的拉曼信号，必须增强激发辐射的电场强度。 表面增强拉曼散射（Sers）方法在宏观体系中的应用已被证明是非常成功的。 目前的探索性研究将探讨应用Sers过程来表征纳米域中的铁电薄膜的方法。

This Small Grants for Exploratory Research (SGER) award will support a project investigating the application of near-field enhanced micro-Raman Spectroscopy to ferroelectric thin films. Micro-Raman spectroscopy has been shown to be a useful tool for material characterization. However, in transparent ferroelectric thin films grown on insulating substrates the Raman signal drops to undetectable levels. In some materials the Raman signal can be enhanced through the use of the surface enhanced Raman scattering effect (SERS). An attempt will be made to create SERS conditions in thin ferroelectric films of interest by introducing metallic (Au) nano-particles at the surface, the substrate interface, or within the bulk of the films. A second method will employ a gold plated atomic force microscope (AFM) tip to act as a single metallic particle placed on the back side of a transparent substrate. This second method will also be explored as a way to map out, on the nano-scale, properties of extended ferroelectric thin films.%%%Ferroelectric materials play a great role in many technological applications. The next generation of advanced and compact integrated electronics will require thin films of new classes of complex electroceramic and other optoelectronic materials. Recent developments in material processing and thin film fabrication techniques have made available high quality thin films suitable for these applications. Ferroelectrics are a class of electroceramics that offer a wide range of useful properties that could be used to develop devices, such as smart sensors and structures, radiation-hard non-volatile computer memories, and pyroelectric detectors. Successful implementation of these devices will require materials with well-defined properties and device figures of merit. Micro-Raman spectroscopy has emerged as an excellent non-destructive tool for comprehensive materials characterization by investigating the effects of size, stress/strain, temperature, pressure, and electric field on the dynamic scattering behavior. To obtain Raman signals of measurable strength from thin films, it is necessary to enhance the electric field strength of the exciting radiation. The method of surface enhanced Raman scattering (SERS) has proven to be extremely successful in applications to macroscopic systems. The present exploratory research will investigate methods of applying the SERS process to characterize ferroelectric thin films in the nano-domain..***