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arXiv · 2502.10343

Impurity-induced moment freezing in NaFe$_x$Ru$_{1-x}$O$_2$

Alon Hendler Avidor·Brenden R. Ortiz·Paul M. Sarte·Qiang Zhang·Stephen D. Wilson
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Abstract

We report the impact of magnetic impurity substitution on the quantum disordered magnetic ground state of NaRuO$_2$. Local $S=5/2$ moments are introduced into the frustrated triangular lattice of $J_{eff}=1/2$ Ru moments via Fe-substitution in NaFe$_x$Ru$_{1-x}$O$_2$, and the evolution of the magnetic ground state is reported. Local spin freezing associated with conventional spin glass behavior is observed upon Fe substitution, marking an impurity-induced freezing of the primarily dynamic magnetic ground state in NaRuO$_2$. Furthermore, local Fe moments induce a Curie-Weiss magnetic behavior in the uniform magnetic susceptibility, and the local moment magnitude is best described by dynamic Ru moments polarized about impurity sites. Our results establish an impurity-doping phenomenology consistent with inherently dynamic moments in NaRuO$_2$ that are pinned by local magnetic impurities, similar to ``swiss cheese" models of impurity-substituted copper oxides.

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Alon Hendler Avidor, Brenden R. Ortiz, Paul M. Sarte, Qiang Zhang, Stephen D. Wilson. 2025-02-14. Impurity-induced moment freezing in NaFe$_x$Ru$_{1-x}$O$_2$. https://doi.org/10.1103/physrevmaterials.9.024404

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