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

量子材料非凡的磁性和电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，既包括晶格的空间群，也包括晶格中离子的点群对称性，决定了低温下可能出现的奇异态(如拓扑电子态、量子自旋液体或非传统超导体)。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第一步。绝大多数实验室x射线衍射仪，包括我们的，只能在室温下操作，这极大地限制了它们的使用。无法在高温和低温下进行X射线衍射测量，从两个方面阻碍了我们的进展：(I)一些材料在室温以下会经历结构相变，因此我们缺乏必要的结构知识来了解其低温量子态，(Ii)一些材料的合成需要微调的温度分布，而原位研究它们的形成是我们推导适当条件的唯一有效方法。要获得回答这些问题的数据，目前我们需要在同步加速器x射线或中子设备上获取束流时间。这一过程可能需要6-12个月的时间才能完成，这极大地减缓了我们的研究进度，有时还会使项目变得不可行。我们计划为我们最先进的Bruker D8高级粉末X射线衍射仪购买一个低温(液氮，低至-180摄氏度)和一个高温(炉子，高达1300摄氏度)样品台，极大地扩大了其用途。我们的衍射仪是一种新安装的系统，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，也可以研究具有非常细微结构扭曲的样本。我们建议获得的两个温度级在设计上完全模块化，共享许多重叠的组件，因此，获得这两个温度级的成本比单独获得其中一个的成本略有增加。通过建立可靠的培训协议、标准操作程序和定期维护时间表，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在我们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与其晶体对称性的相互作用。它们将是每年约15名实习生(本科生、研究生和博士后)项目的组成部分。对于实验物理学家来说，非环境样品环境的专业知识是一项关键技能，他们对加拿大蓬勃发展的量子技术部门的需求很高。

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.