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

矿物中的痕量缺陷，包括代表初期辐射损伤的辐射诱发缺陷，对材料的颜色、密度、流变性、稳定性、导电性和导热性、磁性、地震速度等产生了深远的影响。矿物和其他材料中的痕量缺陷在地球科学中也有广泛的应用，从地球化学模拟到剂量学、地质年代学、重金属污染的修复、核废料处理和矿产勘探。这项研究计划旨在基本了解矿物和其他地球材料中的微量缺陷，重点是它们的电子结构、磁性和新的应用。科学方法包括实地调查，以查明重要地质应用的痕迹缺陷和/或与环境直接相关。实验室实验旨在补充实地调查，并为光谱研究提供合成材料。然后利用多种分析技术，特别是电子顺磁共振(EPR)光谱和同步辐射X射线吸收光谱(XAS)，以及第一性原理理论计算，对所选矿物及其合成类似物中的痕量缺陷进行了定量表征。下一个供资周期的具体研究目标是：1)对石英中新的辐射引起的缺陷进行实验和理论研究，2)在普通硫酸盐和磷酸盐中吸收和形成重金属，以及3)开发用于研究地幔中铁自旋动力学的原位高温EPR技术。这项关于发现和基本了解矿物和相关材料中缺陷的研究计划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具有创新性。此外，这一研究项目为在多学科环境中培养高素质人才提供了一个极好的机会。

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.