Solid State Chemistry of Rare-Earth and Intermetallic Compounds

金属构成了元素周期表中的绝大多数元素。一般来说，仍然很难预测金属如何与其他金属反应，以及它们形成的化合物的组成、结构和性质是什么。然而，这些“金属间化合物”对推动人类进步起了极其重要的作用，从几千年前我们的祖先制造的青铜工具，到我们现在认为理所当然的先进材料，如计算机和电子设备，它们在历史上走过了伟大的历程。在我们的研究中，我们寻求发现新的金属间化合物，对它们的化学键有一个基本的了解，将它们的原子排列与它们的物理性质联系起来，并确定有希望的候选材料应用。我们研究的一组重要金属是“稀土”元素，它在许多能源、通信和国防应用中用作催化剂、磁铁和荧光粉。由于全球稀土金属的生产绝大多数集中在中国（约97%），因此减少供应脆弱性的一个策略是投资研发，寻找稀土的新技术应用，从而使在加拿大开采稀土变得更具经济可行性。我们将研究稀土金属、过渡金属和15组类金属的组合，目标是可能导致新的超导体（可以允许无电阻电流）和热电材料（可以从废热中产生电力）的晶体结构。实验方法包括在非常高的温度下（通常接近1000°C!）反应金属，通过x射线衍射技术解开复杂的晶体结构，测量电学和磁学性质，并进行量子计算。由于学生将成为固态化学、物理和材料科学等不同领域的专家，因此他们具备在先进材料研究领域从事职业的多功能性。

Metals constitute the vast majority of elements in the periodic table. In general, it is still difficult to predict how metals will react with other metals, and what will be the compositions, structures, and properties of the compounds they form. Yet, these "intermetallic compounds" have been enormously important for advancing human progress, traversing great arcs in history starting from the bronze tools manufactured by our forebears millenia ago, to the advanced materials we now take for granted such as computers and electronic devices. In our research, we seek to discover new intermetallics, to develop a fundamental understanding of their chemical bonding, to relate their atomic arrangements to their physical properties, and to identify promising candidates for materials applications. An important group of metals we study are the "rare-earth" elements, which are used for catalysts, magnets, and phosphors in many energy, communications, and defense applications. Because the global production of rare-earth metals is concentrated overwhelmingly (>97%) in China, a strategy to reduce supply vulnerability is to invest in R&D to find new technological applications of rare-earths so that their extraction within Canada becomes more economically viable. We will examine combinations of rare-earth metals, transition metals, and group 15 metalloids, targeting crystal structures that are likely to lead to new superconductors (which can allow resistanceless flow of electricity) and thermoelectric materials (which can generate electrical power from waste heat). The experimental approach involves reacting metals at very high temperatures (often close to 1000 °C!), unravelling the complex crystal structures through X-ray diffraction techniques, measuring electrical and magnetic properties, and performing quantum calculations. Because students become experts in diverse areas of solid state chemistry, physics, and materials science, they possess the versatility that is critical for careers in the advanced materials research sector.