A route to transparent bulk metals

Abstract Hypothetical compounds based on a sapphire host are investigated with respect to their structural as well as electronic features. The results are obtained by electronic structure calculations within density functional theory and the generalized gradient approximation. A quarter of the Al atoms in Al₂O₃ is replaced by a 4d transition metal M ion, with d⁰ to d⁹ electronic configuration. We perform structure optimizations for all the compounds and analyze the electronic states. Due to the sizeable band gap of the Al₂O₃ host, we can identify promising candidates for transparent bulk metals. We explain the mechanisms leading to this combination of materials properties. (© 2012 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)