Solid State Chemistry of Rare-Earth and Intermetallic Compounds

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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.