Experimental and theoretical studies of trace defects in minerals and other Earth materials

矿物中的微量缺陷，包括代表早期辐射损伤的辐射诱发的各种缺陷，对材料的颜色、密度、流变性、稳定性、电导率和导热性、磁性、地震速度等特性产生深远的影响。矿物和其他材料中的微量缺陷在地球科学中也有广泛的应用，从地球化学建模到剂量学、地质年代学、重金属污染的修复、核废料处理和矿物勘探。该研究项目旨在对矿物和其他地球材料中的微量缺陷进行基本了解，重点是它们的电子结构、磁性和新应用。科学方法包括实地调查，以确定重要地质应用和/或直接环境相关的痕量缺陷。实验室实验旨在补充实地调查，并为光谱学研究提供合成材料。然后通过使用多种分析技术，特别是电子顺磁共振（EPR）光谱和同步加速器x射线吸收光谱（XAS）以及第一性原理理论计算，对选定矿物及其合成类似物中的微量缺陷进行定量表征。下一个资助周期的具体研究目标是：1)石英中新的辐射诱导缺陷的实验和理论研究；2)常见硫酸盐和磷酸盐中重金属的吸收和形成；3)开发用于研究地幔中铁自旋动力学的原位高压-高温EPR技术。这个关于发现和基本理解矿物和相关材料缺陷的研究项目在加拿大地球科学界是独一无二的，在探索实验和理论的前沿方面都是创新的。此外，该研究项目为在多学科环境中培养高素质人才提供了极好的机会。

Trace defects, including radiation-induced varieties representing incipient radiation damage, in minerals exert profound impacts on material properties such as color, density, rheology, stability, electrical and thermal conductivity, magnetism, seismic velocity, and many more. Trace defects in minerals and other materials also have a wide range of applications in Earth sciences from geochemical modeling to dosimetry, geochronology, remediation of heavy metalloid contamination, nuclear waste disposal, and mineral exploration. This research program is directed towards fundamental understanding of trace defects in minerals and other Earth materials, with emphasis on their electronic structures, magnetic properties, and novel applications. Scientific approach includes field-based investigations to identify trace defects of important geological applications and/or direct environmental relevance. Laboratory experiments are designed to complement field-based investigations and to provide synthetic materials for spectroscopic studies. Trace defects in selected minerals and their synthetic analogues are then characterized quantitatively by use of multiple analytical techniques, particularly electron paramagnetic resonance (EPR) spectroscopy and synchrotron X-ray absorption spectroscopy (XAS), and first-principles theoretical calculations. Specific research objectives for the next-funding cycle are: 1) experimental and theoretical studies of new radiation-induced defects in quartz, 2) uptake and speciation of heavy metalloids in common sulfates and phosphates, and 3) development of in-situ high-pressure-temperature EPR techniques for investigating iron spin dynamics in the Earth's mantle. This research program on the discovery and fundamental understanding of defects in minerals and related materials is unique in the Canadian Earth science community and is innovative in exploring the frontiers of both experiments and theory. Also, this research program provides an excellent opportunity for the training of highly qualified personnel in a multidisciplinary environment.