Epitaxial growth, optical and electrical conductivity of the metallic pyrochlore Bi2Ru2O7 on Y-stabilized ZrO2 substrate

Epitaxial heterostructures composed of complex correlated metal oxides, grown along specific crystallographic orientations, offer a route to investigating emergent phenomena such as topological states and spin liquids through geometrical lattice engineering. A2Ru2O7 pyrochlore ruthenates, in particular, exhibit metal–insulator transition with varying A cation, whose mechanism is not fully understood. We report on the epitaxial growth, structural electrical properties metallic bismuth ruthenate heterostructures, both [001] [111] directions. Ordered thin films were obtained highly oriented texture Density functional theory calculations electronic band structure density indicated that Bi2Ru2O7 semimetallic hybridization Ru 4d Bi 6p orbitals via anion network at Fermi energy was responsible for metallicity. Electrical conductivity measurements confirmed compound weakly metallic, agreement reported stoichiometric bulk compound. The carrier concentration mobility electrons compared favorably previous reports material indicate strong electron–electron interactions. measured computed optical conductivities found share coincident spectral features confirm correlation. Comparison two distinct orientations indicates differences cannot be attributed crystalline quality or dislocations may anisotropy Bi2Ru2O7. This study will enable access kagome arising naturally 111 planes B cation sublattice, which used uncover properties.