paper

High-pressure synthesis of Ba $_{2}$ RhO $_{4}$ , a rhodate analogue of the layered perovskite Sr-ruthenate

arXiv:2010.06556 · doi:10.1103/PhysRevMaterials.5.015001

Abstract

A new layered perovskite-type oxide Ba $_{2}$ RhO $_{4}$ was synthesized by a high-pressure technique with the support of convex-hull calculations. The crystal and electronic structure were studied by both experimental and computational tools. Structural refinements for powder x-ray diffraction data showed that Ba $_{2}$ RhO $_{4}$ crystallizes in a K $_{2}$ NiF $_{4}$ -type structure, isostructural to Sr $_{2}$ RuO $_{4}$ and Ba $_{2}$ IrO $_{4}$ . Magnetic, resistivity, and specific heat measurements for polycrystalline samples of Ba $_{2}$ RhO $_{4}$ indicate that the system can be characterized as a correlated metal. Despite the close similarity to its Sr $_{2}$ RuO $_{4}$ counterpart in the electronic specific heat coefficient and the Wilson ratio, Ba $_{2}$ RhO $_{4}$ shows no signature of superconductivity down to 0.16 K. Whereas the Fermi surface topology has reminiscent pieces of Sr $_{2}$ RuO $_{4}$ , an electron-like e $_{g}$ -( $d_{x^{2} - y^{2}}$ ) band descends below the Fermi level, making of this compound unique also as a metallic counterpart of the spin-orbit-coupled Mott insulator Ba $_{2}$ IrO $_{4}$ .

8 pages, 6 figures

High-pressure synthesis of Ba2​RhO4​, a rhodate analogue of the layered perovskite Sr-ruthenate

Abstract

High-pressure synthesis of Ba $_{2}$ RhO $_{4}$ , a rhodate analogue of the layered perovskite Sr-ruthenate