MRI: Acquisition of a Cryogen-Free Physical Properties Measurement System (PPMS DynaCool) for Quantum Materials Research and Education at NSU

该主要研究仪器（MRI）奖将用于购买和安装无低温物理特性测量系统（PPMS），该系统将用于新量子材料和器件的制造和表征方面的研究和教育培训。该仪器将位于诺福克州立大学麦克德蒙德应用研究中心（MCAR），供教师和学生使用。它也将是汉普顿路地区唯一的同类仪器，MCAR位于中心位置，距离其他六所大学、四所社区学院、托马斯杰斐逊国家加速器设施、美国宇航局兰利研究中心和东弗吉尼亚医学院不到45分钟的车程，这些地方都没有这种设备。PPMS系统将用于在精确控制的环境（包括温度和外加磁场）中表征基本材料特性和器件性能。该系统将对至少20名NSU材料科学与工程研究生项目的硕士和博士学生以及30多名NSU STEM专业本科生的教育、研究培训和专业发展产生直接影响，其中大多数参与者来自传统上在STEM领域代表性不足的群体。对本科生的影响将来自个别学生的研究项目和通过为高级实验课程开发的模块进行的研究训练。该主要仪器是诺福克州立大学材料研究基础设施的重要补充，将支持多种跨学科材料研究项目，包括量子材料的基础研究、非中心对称磁体中新型自旋纹理的特征、拓扑效应和临界现象、新型有机半导体和混合材料的表征。用于生物医学应用的磁性纳米颗粒和稀土磁热和磁弹性材料薄膜。物理性能测量系统配备了集成的传导冷却超导14特斯拉磁体，该磁体被认为是最先进的高磁场和低温系统，具有卓越的稳定性和灵敏度。该系统可以在不到40分钟内将样品室从室温冷却到1.9 K。稀释冰箱插入提供了进行低至50 mK测量的能力，这对于探测材料中的量子力学现象至关重要。样品室可容纳各种测量插入件，所有这些插入件都允许在全范围的磁场和温度下在计算机控制下全自动数据采集。一个多功能探头适应自定义实验，和一个水平样品旋转器允许磁电阻测量作为一个函数的样品方向相对于磁场。该系统能够测量电阻率、导热系数、霍尔效应和其他热电性能，以及磁化率和磁化强度。该系统的闭式循环无低温特性确保了设备的经济高效和可靠的长期运行。该奖项反映了美国国家科学基金会的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

Non-Technical AbstractThis Major Research Instrumentation (MRI) award will enable the purchase and installation of a Cryogen-Free Physical Property Measurement System (PPMS) that will be used for research and education training in fabrication and characterization of new quantum materials and devices. The instrument will be located in the Norfolk State University McDemmond Center for Applied Research (MCAR) and will be available for use by faculty and students. It will also be the only instrument of its kind in the Hampton Roads area with MCAR being centrally a location within a 45 minute drive of six other universities, four community colleges, the Thomas Jefferson National Accelerator Facility, the NASA Langley Research Center, and the Eastern Virginia Medical School, none of which have local access to this type of equipment. The PPMS system will be used to characterize both basic materials properties and device performance in an accurately controlled environment including temperature and applied magnetic field. This system will have a direct impact on the education, research training, and professional development of at least 20 MS and PhD students in the NSU material science and engineering graduate programs, and over 30 NSU undergraduate STEM majors with the majority of all the participants coming from groups traditionally underrepresented in STEM fields. The impact on undergraduates will result from individual student research projects and research training through modules developed for advanced laboratory courses.Technical AbstractThis major instrumentation is an important addition to Norfolk State University’s materials research infrastructure and will support diverse interdisciplinary materials research projects ranging from fundamental studies of quantum materials, signatures of novel spin-textures in noncentrosymmetric magnets, topological effects and critical phenomena, characterization of novel organic semiconductor and hybrid materials, magnetic nanoparticles for biomedical applications and thin films of rare-earth magnetocaloric and magneto-elastic materials. The Physical Properties Measurement System is equipped with an integrated conduction-cooled superconducting 14 Tesla magnet which is recognized as state-of-the-art high magnetic field and low-temperature system with exceptional stability and sensitivity. This system can cool the sample chamber from room-temperature down to 1.9 K in less than 40 minutes. A dilution refrigerator insert provides the capability to conduct measurements down to 50 mK, essential for probing quantum mechanical phenomena in materials. The sample chamber accommodates a wide range of measurement inserts, all of which allow fully automated data acquisition under computer control over the full range of magnetic field and temperature. A multi-function probe accommodates custom experiments, and a horizontal sample rotator allows magnetoresistance measurements as a function of sample orientation relative to magnetic field. This system provides the capability to measure electrical resistivity, thermal conductivity, Hall Effect, and other thermoelectric properties, as well as susceptibility and magnetization. The closed-cycle cryogen-free feature of this system ensures cost-effective and reliable long-term operation of the equipment.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.