Development of a Variable Temperature, High Frequencey NMR System for Materials Research

9704225 Meisel该奖项为开发一种新的变温高频核磁共振（NMR）仪器提供了支持，该仪器将被安置在佛罗里达大学盖恩斯维尔校区正在建造的新物理大楼中。该设备将能够在室温下提供宽范围的磁场（高达8.5 T，均匀性为10-6），孔径为50毫米。一个宽带高频（5到350兆赫）光谱仪将是仪器的一个组成部分。将开发各种探针，使NMR可以跨越25 mK到400 k的温度。这种新仪器将作为探测微观电磁相互作用的工具，这是我们理解新型低维磁体（例如霍尔丹间隙和自旋阶梯材料）和新型磁性系统（例如近道绝缘体和磁性/非磁性多层材料）的基础。特别是，该仪器提供的数据可能是任何其他已知的实验探头无法获得的。此外，当新的极端磁场、温度和压力似乎是研究的自然延伸时，可以在国家强磁场实验室（NHMFL）继续进行实验。该系统（特别是分光仪）的设计方式将使其与NHMFL在更高频率和磁场下使用的仪器兼容。该计划的一个重要组成部分是博士后、研究生和本科生的教育和培训。研究团队成员接受过多种现代跨学科领域的培训，包括（但不限于）低温学，电子学，超高真空技术，核磁共振，宏观和微观表面科学技术，以及新的化学合成方案。当初级研究人员离开小组时，他们准备解决未来未知的技术和科学问题。＊＊＊

9704225 Meisel This award provides support to develop a new variable temperature, high-frequency Nuclear Magnetic Resonance (NMR) instrument that will be housed in the new physics building that is being constructed on the Gainesville campus at the University of Florida. The device will have the capability of providing a wide range of magnetic field (up to 8.5 T with 10-6 homogeneity) in a 50 mm clear bore at room temperature. A broadband high frequency (5 to 350 MHz) spectrometer will be an integral part of the instrument. A variety of probes will be developed to allow NMR to span temperatures from 25 mK to 400 K. %%% This new instrument will serve as a tool to probe the microscopic electromagnetic interactions that are fundamental to our understanding of new low dimensional magnets (e.g. Haldane gap and spin-ladder materials) and novel magnetic systems (e.g. Kondo insulators and magnetic/nonmagnetic multilayers). In particular, the data provided by this instrument may not be obtainable by any other known experimental probe. In addition, when new extremes of magnetic field, temperature, and pressure seem to be natural extensions of the research, the experiments may be continued at the National High Magnetic Field Laboratory (NHMFL). The system (especially the spectrometer) is being designed in a manner which will make it compatible with the instrumentation used at the NHMFL at higher frequencies and magnetic fields. An important component of the proposed program is the education and training of postdoctoral fellows, graduate students, and undergraduate students. Members of the researcher team are trained in a variety of modern cross-disciplinary fields, including (but not limited to) cryogenics, electronics, ultra-high vacuum technology, NMR, macroscopic and microscopic surface science techniques, and new chemical synthesis protocols. When the junior researchers leave the group, they are prepared to tackle the heretofore unknown technic al and scientific questions of the future. ***