Development of a Novel 67ZN Mossbauer Spectrometer for Basic Materials Research

开发用于基础材料研究的新型 67ZN 穆斯堡尔谱仪

• 批准号: 9704228
• 负责人: Punit Boolchand
• 金额: --
• 依托单位: University of Cincinnati Main Campus
• 依托单位国家: 美国
• 项目类别: Continuing grant
• 财政年份: 1997
• 资助国家: 美国
• 起止时间: 1997-09-15 至 2001-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=9704228&HistoricalAwards=false
• 关键词: Development; Novel; 67ZN; Mossbauer; Spectrometer

9704228 Boolchand This award provides partial support for implementing a new concept of a 67Zn M ssbauer spectrometer which will yield significantly larger (at least a factor of 20) signal to noise ratios than hitherto possible using standard velocity drives in transmission measurements of materials. The novel features of the present concept includes (a) use of a phase modulation drive which avoids any relative motion between source and absorber matrix, and (b) time-filter the re-emitted radiation to discriminate the short lived (10-12s) non-resonant radiation from the long-lived (10-5s) resonant one to enhance the signal to noise ratio. Feature (a) will be implemented by using a rotating wheel consisting of Al wedges which interrupt the -beam from a source to modulate the energy with respect to a stationary absorber. Feature (a) will also permit region of interest velocity scans, an option that will permit a more efficient collection of information with the short-lived M ssbauer parents (67Ga and 67Cu). Feature (b) will be implemented by using a shutter wheel with narrow slits, that will block the -beam from the source while a scintillation detector registers the re- emitted -rays and conversion electrons from the absorber. Implementation of these features at 4.2K will be done by supporting the wheels in an exchange gas column of a liquid Helium dewar. The project will demonstrate the enormous cost advantage of obtaining Zn spectra using the new spectrometer and should make possible obtaining spectra of Zn compounds of normal enrichment. Such an experimental facility will have important consequences in the field of basic materials research. High resolution studies of Zn based inorganic compounds in absorption and Cu- and Ga-based compounds in emission spectroscopy will permit addressing outstanding materials science issues in a wide variety of materials including II-VI, III-V and II-IV-V2 semiconductors, cuprate superconductors, galvanization of steels, Zn-ferrites, Zn-spinels and zinc based enzymes.

小行星9704228 该奖项为实施67 Zn穆斯堡尔谱仪的新概念提供了部分支持，该谱仪将产生比迄今为止在材料透射测量中使用标准速度驱动器更大（至少20倍）的信噪比。 本概念的新颖特征包括（a）使用相位调制驱动器，其避免源和吸收器矩阵之间的任何相对运动，以及（B）对重新发射的辐射进行时间滤波，以将短寿命（10- 12 s）的非共振辐射与长寿命（10- 5 s）的共振辐射区分开，从而增强信噪比。 特征（a）将通过使用由铝楔组成的旋转轮来实现，所述铝楔中断来自源的电子束以相对于固定吸收器调制能量。 特征（a）还将允许感兴趣区域的速度扫描，这是一种允许更有效地收集短寿命穆斯堡尔母体（67 Ga和67 Cu）信息的选择。 特征（B）将通过使用具有窄缝的快门轮来实现，该快门轮将阻挡来自源的电子束，而闪烁检测器记录来自吸收体的再发射的电子束和转换电子。 在4.2K下实现这些功能将通过在液氦杜瓦瓶的交换气柱中支撑轮子来完成。 该项目将证明使用新的光谱仪获得锌光谱的巨大成本优势，并应能够获得正常富集的锌化合物的光谱。 这样的实验设施将在基础材料研究领域产生重要影响。 高分辨率的研究锌基无机化合物的吸收和铜和镓基化合物的发射光谱将允许解决突出的材料科学问题，在各种材料，包括II-VI，III-V和II-IV-V2半导体，铜酸盐超导体，镀锌钢， 锌铁氧体、锌尖晶石和锌基酶。