Strong antiferromagnetic interaction owing to a large trigonal distortion in the spin-orbit-coupled honeycomb lattice iridate <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:mrow><mml:mi>CdIr</mml:mi><mml:msub><mml:mi mathvariant="normal">O</mml:mi><mml:mn>3</mml:mn></mml:msub></mml:mrow></mml:math>
Yuya Haraguchi, Hiroko Aruga Katori
Abstract
We investigated the magnetic properties of the ilmenite-type iridate $\mathrm{CdIr}{\mathrm{O}}_{3}$ with a honeycomb lattice formed by $\mathrm{I}{\mathrm{r}}^{4+}$ ions prepared via a solid-state metathesis. The magnetization measurements made using the powder sample reveal a large effective magnetic moment and a fairly strong antiferromagnetic interaction, indicating a deviation from the Kitaev model. Considering the relationship between magnetism and crystal structure in $\mathrm{CdIr}{\mathrm{O}}_{3}$, and comparing it with the other ilmenite-type iridates $\mathrm{ZnIr}{\mathrm{O}}_{3}$ and $\mathrm{MgIr}{\mathrm{O}}_{3}$, we conclude that insulating $\mathrm{CdIr}{\mathrm{O}}_{3}$ cannot be described as a ${J}_{\mathrm{eff}}=1/2$ Mott state owing to a metathetically stabilized large trigonal distortion of $\mathrm{Ir}{\mathrm{O}}_{6}$ octahedra.