Defect control in the Heisenberg-Kitaev candidate material NaRuO${}_2$

The combination of geometric frustration, extended hopping, spin-orbit coupling, and a disordered magnetic ground state make NaRuO${}_2$ an attractive Heisenberg-Kitaev candidate material. Historically, NaRuO${}_2$ has been a challenging material to produce, even in polycrystalline form. Here we present synthetic efforts that identify a propensity for Na${}_{\text{Ru}}$ defects to form in NaRuO${}_2$, revealing a full solid-solution between NaRuO${}_2$ and disordered Na${}_2$RuO${}_3$. We report the synthesis of alloys along the Na${}_{3+x}$Ru${}_{3-x}$O${}_6$ solid solution and characterize changes in the bulk magnetization and electron transport as a function of Na-loading. Our results highlight the importance of stoichiometry control in NaRuO${}_2$ when investigating and interpreting this material’s physical properties.