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arXiv · 1005.2926

Epitaxially stabilized iridium spinel oxide without cations in the tetrahedral site

Hiromichi Kuriyama·Jobu Matsuno·Seiji Niitaka·Masaya Uchida·Daisuke Hashizume·Aiko Nakao·Kunihisa Sugimoto·Hiroyuki Ohsumi·Masaki Takata·Hidenori Takagi
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Abstract

Single-crystalline thin film of an iridium dioxide polymorph Ir2O4 has been fabricated by the pulsed laser deposition of LixIr2O4 precursor and the subsequent Li-deintercalation using soft chemistry. Ir2O4 crystallizes in a spinel (AB2O4) without A cations in the tetrahedral site, which is isostructural to lambda-MnO2. Ir ions form a pyrochlore sublattice, which is known to give rise to a strong geometrical frustration. This Ir spinel was found to be a narrow gap insulator, in remarkable contrast to the metallic ground state of rutile-type IrO2. We argue that an interplay of strong spin-orbit coupling and a Coulomb repulsion gives rise to an insulating ground state as in a layered perovskite Sr2IrO4.

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Hiromichi Kuriyama, Jobu Matsuno, Seiji Niitaka, Masaya Uchida, Daisuke Hashizume, Aiko Nakao, Kunihisa Sugimoto, Hiroyuki Ohsumi, Masaki Takata, Hidenori Takagi. 2010-05-17. Epitaxially stabilized iridium spinel oxide without cations in the tetrahedral site. https://doi.org/10.1063/1.3374449

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