Evolution of crystal field and intraionic interactions in the ilmenite $A$IrO${}_3$ ($A$ = Mg, Zn, Cd) and hyperhoneycomb $\beta$-ZnIrO${}_3$

Abstract

Spin-orbit Mott insulators with the $t_{2g}^5$ electron configuration are promising platforms for the Kitaev spin liquid, yet fine-tuning of their crystal structures is essential to suppress non-Kitaev interactions. Here, we investigate the local electronic structures of the ilmenite iridates $A{\mathrm{IrO}}_3$ ($A=\mathrm{Mg},\mathrm{Zn},\mathrm{Cd}$) and the hyperhoneycomb $\beta \text{-}{\mathrm{ZnIrO}}_3$ using Ir $L_3$-edge resonant inelastic x-ray scattering (RIXS). Multiplet analysis of the RIXS spectra reveals a systematic evolution of the crystal field and intraionic interaction parameters upon chemical substitution at the $A$-site. We observe an enhancement of the trigonal distortion with increasing $A$-site ionic radius. This provides a microscopic explanation for the deviation from the ideal $J=1/2$ state and the antiferromagnetic interactions identified in ${\mathrm{CdIrO}}_3$. Furthermore, the local multiplet parameters of ilmenite ${\mathrm{ZnIrO}}_3$ and hyperhoneycomb $\beta \text{-}{\mathrm{ZnIrO}}_3$ are found to be nearly identical, demonstrating that their different magnetic ground states are primarily governed by their distinct lattice structures rather than the single-ion properties. These findings establish a solid foundation for understanding how local crystal-field distortions control the magnetic Hamiltonian in Kitaev candidate materials.

References in corpus (27)

• Anyons in an exactly solved model and beyond
• Mott Insulators in the Strong Spin-Orbit Coupling Limit: From Heisenberg to a Quantum Compass and Kitaev Models
• Quantum Spin Liquids
• Resonant Inelastic X-ray Scattering Studies of Elementary Excitations
• Strong electronic correlations from Hund's coupling
• Kitaev quantum spin liquid - concept and materialization
• $\alpha$-RuCl3: a Spin-Orbit Assisted Mott Insulator on a Honeycomb Lattice
• Relevance of the Heisenberg-Kitaev model for the honeycomb lattice iridates A_2IrO_3
• Spin-Orbit Physics Giving Rise to Novel Phases in Correlated Systems: Iridates and Related Materials
• Magnetic order in $\alpha$-RuCl${}_3$: a honeycomb lattice quantum magnet with strong spin-orbit coupling
• Physics of the Kitaev model: fractionalization, dynamical correlations, and material connections
• Crystal field splitting and correlation effect on the electronic structure of A2IrO3
• Magnetic anisotropy in the Kitaev model systems Na2IrO3 and RuCl3
• Materials design of Kitaev spin liquids beyond the Jackeli-Khaliullin mechanism
• Proximate ferromagnetic state in the Kitaev model material $\alpha$-RuCl${}_3$
• Thermodynamic Evidence of Proximity to a Kitaev Spin-Liquid in Ag${}_3$LiIr${}_2$O${}_6$
• Exotic low-energy excitations emergent in the random Kitaev magnet Cu${}_2$IrO${}_3$
• Magnetic ordering with an XY-like anisotropy in the honeycomb lattice iridates ZnIrO${}_3$ and MgIrO${}_3$ synthesized via a metathesis reaction
• Nonmagnetic $J=0$ State and Spin-Orbit Excitations in K${}_2$RuCl${}_6$
• Strong antiferromagnetic interaction owing to a large trigonal distortion in the spin-orbit-coupled honeycomb lattice iridate CdIrO${}_3$
• Nearly itinerant electronic groundstate in the intercalated honeycomb iridate Ag${}_3$LiIr${}_2$O${}_6$
• Electronic and magnetic properties of iridium ilmenites $A$IrO${}_3$ ($A=$ Mg, Zn, and Mn)
• Quantum paramagnetism in the hyperhoneycomb Kitaev magnet $\beta$-ZnIrO${}_3$
• $J=1/2$ Pseudospins and $d$-$p$ Hybridization in the Kitaev Spin Liquid Candidates Ru$X_3$ ($X$ = Cl, Br, I)
• Non-local features of the spin-orbit exciton in Kitaev materials
• High-temperature magnetic anomaly via suppression of antisite disorder through synthesis route modification in a Kitaev candidate Cu${}_2$IrO${}_3$
• Monoclinic distortion in hyperhoneycomb Kitaev material $\beta$-ZnIrO${}_3$ revealed by improved sample quality