Unveiling the structure and formation of quantum materials via x-ray diffraction with non-ambient temperature stages

通过非环境温度阶段的 X 射线衍射揭示量子材料的结构和形成

• 批准号: RTI-2022-00625
• 负责人: Hallas, Alannah
• 金额: $ 7.78万
• 依托单位: University of British Columbia
• 依托单位国家: 加拿大
• 项目类别: Research Tools and Instruments
• 财政年份: 2021
• 资助国家: 加拿大
• 起止时间: 2021-01-01 至 2022-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=743089
• 关键词: Unveiling; structure; formation; quantum; materials

The remarkable magnetic and electronic properties of quantum materials are inextricably linked with their underlying crystal symmetries. These crystal symmetries, both the space group of the crystal lattice and the point group symmetries of the ions inhabiting that lattice, determine what types of exotic states might emerge at low temperature (e.g. topological electronic states, quantum spin liquids, or unconventional superconductors). Structure determination via x-ray diffraction is thus the crucial first step in characterizing any new material grown in the Quantum Materials Design Lab. The vast majority of laboratory x-ray diffractometers, including ours, can only be operated at room temperature - greatly limiting their utility. The inability to perform x-ray diffraction measurements at high and low temperatures hinders our progress in two distinct ways: (i) some materials will undergo a structural phase transition below room temperature, and hence we lack the essential structural knowledge to understand its low-temperature quantum state, and (ii) the synthesis of some materials require a fine-tuned temperature profile and studying their formation in-situ is the only efficient way for us to deduce the appropriate conditions. Obtaining the data to answer these questions currently requires us to acquire beam time at a synchrotron x-ray or neutron facility. This process can take 6-12 months to complete, dramatically slowing the progress of our research and, at times, rendering projects infeasible. We propose to acquire a low-temperature (liquid nitrogen, down to -180 C) and a high-temperature (furnace, up to 1300 C) sample stage for our state-of-the art Bruker D8 Advance powder x-ray diffractometer, dramatically expanding its utility. Our diffractometer is a newly installed system expected to have a useful lifetime of up to 20 years with best-in-class resolution and sensitivity. Thus, we can study very small samples as well as samples with very subtle structural distortions. The two temperature stages we propose to acquire are completely modular in design, sharing many overlapping components, and as such, the cost of acquiring both is a marginal increase over acquiring either one individually. The long-term sustainability of this equipment will be ensured by establishing robust training protocols, standard operating procedures, and a regular maintenance schedule These two stages will enable us to better control the synthesis of materials discovered in our lab and to better understand the interplay of their quantum behaviors with their crystal symmetries. They will be an integral component of the projects of approximately 15 trainees (undergraduate, graduate, and postdoctoral) per year. Expertise with non-ambient sample environments is a critical skill for experimental physicists, who are in high demand for Canada's burgeoning quantum technology sector.

量子材料卓越的磁性和电子特性与其潜在的晶体对称性有着千丝万缕的联系。这些晶体对称性，包括晶格的空间群和居住在该晶格中的离子的点群对称性，决定了在低温下可能出现什么类型的奇异态（例如拓扑电子态、量子自旋液体或非常规超导体）。因此，通过 X 射线衍射确定结构是表征量子材料设计实验室中生长的任何新材料的关键的第一步。绝大多数实验室 X 射线衍射仪（包括我们的 X 射线衍射仪）只能在室温下操作，这极大地限制了它们的实用性。无法在高温和低温下进行 X 射线衍射测量以两种不同的方式阻碍了我们的进展：（i）一些材料将在室温以下发生结构相变，因此我们缺乏必要的结构知识来理解其低温温度量子态，以及（ii）一些材料的合成需要微调温度曲线，并且研究它们的原位形成是我们推断适当条件的唯一有效方法。目前，要获得回答这些问题的数据，我们需要在同步加速器 X 射线或中子设施中获取束流时间。此过程可能需要 6-12 个月才能完成，这极大地减慢了我们的研究进度，有时甚至导致项目变得不可行。我们建议为我们最先进的 Bruker D8 Advance 粉末 X 射线衍射仪购买低温（液氮，低至 -180 C）和高温（炉，高达 1300 C）样品台，极大地扩展了它的效用。我们的衍射仪是新安装的系统，预计使用寿命长达 20 年，具有一流的分辨率和灵敏度。因此，我们可以研究非常小的样本以及具有非常微妙的结构扭曲的样本。我们建议购买的两个温度阶段在设计上完全模块化，共享许多重叠的组件，因此，购买这两个温度阶段的成本比单独购买其中任何一个的成本略有增加。通过建立健全的培训协议、标准操作程序和定期维护计划，将确保该设备的长期可持续性。这两个阶段将使我们能够更好地控制实验室中发现的材料的合成，并更好地了解它们的量子行为及其晶体对称性。他们将成为每年约 15 名受训人员（本科生、研究生和博士后）项目的组成部分。非环境样本环境方面的专业知识是实验物理学家的一项关键技能，加拿大蓬勃发展的量子技术领域对实验物理学家的需求量很大。