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

这笔赠款支持购买一台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，可见范围)，以补充FT-拉曼光谱仪的1064 nm线；(2)微采样。多个激光波长是通过标准的633 nm Ne-He激光器实现的。将使用陷波滤光片，以达到50厘米以内。实验(-1)413、568和647激光线路。为了最大限度地降低成本，光谱仪的标准工作模式将是微采样显微镜。对于大块样本，这提供了在空间上解析光谱的能力，以查找样本中的纹理和变化。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调焦和XY扫描显微镜工作台，能够有效地收集光谱，并能够对样品表面执行自动XY扫描，从而极大地扩展了光谱仪的能力和灵活性。最后，加热和冷冻阶段允许在-196至600摄氏度之间进行与温度相关的研究，这使得能够检查样品的热稳定性以及温度对材料结构的影响。这种激光拉曼光谱仪将在本科生和研究生教学中大量使用，作为材料表征课程的核心部件，该课程涵盖材料表征的热和光谱技术。通过这种方式，MSE系的几乎每个学生都将使用这些新的仪器系统。新的光谱仪还将用于夏季NSF-REU现场，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。许多研究人员已经证明，拉曼光谱与显微采样能力相结合是研究块状样品、表面样品和微量样品的关键分析工具。它的力量、灵活性和非破坏性使其几乎可以广泛应用于所有种类的材料。随着高效、可调谐、可靠、紧凑和经济实惠的激光器与高分辨率和坚固耐用的光栅单色仪和固态CCD探测器相结合的发展，激光拉曼光谱的使用已经从高技能光谱学家的领域转变为执业材料科学家和工程师的常规使用。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(低温和高温、低压和高压、低磁场和高磁场等)具有很大的灵活性，固态样品的分辨率通常非常高，而且具有非破坏性。结合微采样拉曼显微镜，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、织构，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.