Acquisition of a Comprehensive Multi-Wavelength Laser Raman System for Materials Education and Research

这笔赠款支持购买研究级多波长激光拉曼光谱仪。激光拉曼光谱仪有两个主要特点：(1) 多个激光波长（400 至 800 nm，可见光范围），以补充 FT-拉曼光谱仪的 1064 nm 谱线；(2) 微采样。多个激光波长是通过标准 633 nm Ne He 激光器实​​现的。将使用陷波滤波器将距离控制在 50 厘米以内。实验值。 413、568 和 647 激光线的 (-1)。为了最大限度地降低成本，光谱仪的标准操作模式将是微采样显微镜。对于大块样品，这提供了空间解析光谱以寻找样品中的纹理和变化的能力。对于微量样品，这提供了所需的微米级分辨率。该显微镜配备了自动对焦和 xy 扫描显微镜载物台，可有效收集光谱，并能够对样品表面进行自动 xy 扫描，从而大大扩展了光谱仪的功能和灵活性。最后，加热和冷冻阶段允许在 -196 至 600 摄氏度之间进行温度依赖性研究。这可以检查样品的热稳定性以及温度对材料结构的影响。该激光拉曼光谱仪将大量用于本科生和研究生教学，作为材料表征课程的核心组成部分，涵盖表征材料的热和光谱技术。这样，MSE 系的几乎每个学生都将使用这些新的仪器系统。新的光谱仪也将用于 NSF-REU 夏季站点，来自全国各地的 12 名本科生来到 ISU 学习半导体材料和器件。许多研究人员已证明，拉曼光谱与微采样能力相结合是研究本体、表面和微样品的关键分析工具。其强大的功能、灵活性和非破坏性使其可以广泛用于几乎所有类别的材料。高效、可调谐、可靠、紧凑和具有成本效益的激光器与高分辨率、坚固耐用的光栅单色仪和固态 CCD 探测器相结合的最新进展，使激光拉曼光谱的使用从高技能光谱学家的领域转移到实践材料科学家和工程师的日常使用。拉曼光谱特别适合用于材料研究，因为样品制备最少、采样条件具有广泛的灵活性（低温和高温、低压和高压、低磁场和高磁场等）、固态样品通常非常清晰的解析线及其非破坏性。与微采样拉曼显微镜相结合，拉曼光谱可以非常有效地用于仔细研究表面化学、结构、形态、纹理甚至应力。

This grant supports acquisition of a research grade multi-wavelength laser Raman spectrometer. The laser Raman spectrometer has two main features: (1) multiple laser wavelengths (400 to 800 nm, visible range) to complement the 1064 nm line of the FT-Raman spectrometer, and (2) microsampling. The multiple laser wavelengths is accomplished through a standard 633 nm Ne He laser. Notch filters will be used to get within 50-cm. exp. (-1) of the 413, 568, and 647 laser lines. To minimize the cost, the standard operating mode of spectrometer will be the microsampling microscope. For bulk samples, this provides the ability to spatially resolve the spectra to look for texture and variation in the sample. For microsamples, this provides the micron level resolution required. The microscope is equipped with an auto-focusing and xy-scan microscope stage that enables efficient collection of the spectra combined with the ability to perform automated xy-scanning of the surfaces of samples, greatly extending the power and flexibility of the spectrometer. Finally, a heating and freezing stage allows temperature dependent studies to be conducted from -196 to 600 degrees C. This enables examination of thermal stability of samples as well as the effect of temperature on the material structure. This laser Raman spectrometer will be heavily used in undergraduate and graduate teaching, as a core component in materials characterization courses that cover thermal and spectroscopic techniques of characterizing materials. In this way nearly every student in the MSE department will use these new instrument systems The new spectrometer will also be used for a summer NSF-REU site, where 12 undergraduate students from all over the country come to ISU to learn about semi-conducting materials and devices.Raman spectroscopy combined with microsampling capability has been shown by many researchers to be a critical analytical tool in the study of bulk, surface, and micro samples. Its power, flexibility, and non-destructive nature lend itself to wide spread use for nearly all classes of materials. Recent advances in the development of highly efficient, tunable, reliable, compact, and cost effective lasers combined with high resolution and rugged grating monochromators and solid state CCD detectors has moved the use of laser Raman spectroscopy from the realm of highly skilled spectroscopists into routine use by practicing materials scientists and engineers. Raman spectroscopy is particularly well suited for use in materials research due to minimal sample preparation, wide flexibility of sampling conditions (low and high temperatures, low and high pressure, low and high magnetic field, etc.), generally very sharp well resolved lines for solid state samples, and its non-destructive nature. Combined with a microsampling Raman microscope, Raman spectroscopy can be used extremely effectively in the careful study of surface chemistry, structure, morphology, texture, and even stress.