Covalency and vibronic couplings make a nonmagnetic j=3/2 ion magnetic

Abstract

For 4$d^1$ and 5$d^1$ spin-orbit-coupled electron configurations, the notion of nonmagnetic j=3/2 quartet ground state discussed in classical textbooks is at odds with the observed variety of magnetic properties. Here we throw fresh light on the electronic structure of 4$d^1$ and 5$d^1$ ions in molybdenum- and osmium-based double-perovskite systems and reveal different kinds of on-site many-body physics in the two families of compounds: while the sizable magnetic moments and $g$ factors measured experimentally are due to both metal $d$-ligand $p$ hybridization and dynamic Jahn-Teller interactions for 4$d$ electrons, it is essentially $d$-$p$ covalency for the 5$d^1$ configuration. These results highlight the subtle interplay of spin-orbit interactions, covalency and electron-lattice couplings as the major factor in deciding the nature of the magnetic ground states of 4$d$ and 5$d$ quantum materials. Cation charge imbalance in the double-perovskite structure is further shown to allow a fine tuning of the gap between the $t_{2g}$ and $e_g$ levels, an effect of much potential in the context of orbital engineering in oxide electronics.

6 pages, 2 figures

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Cited by in corpus (12)

• Exchange interactions, Jahn-Teller coupling, and multipole orders in pseudospin one-half $5{\mathbf{d}}^2$ Mott insulators
• Dynamic Jahn-Teller effect in the strong spin-orbit coupling regime
• Interplay between multipolar spin interactions, Jahn-Teller effect and electronic correlation in a $J_{eff}=\frac{3}{2}$ insulator
• The origin of magnetism in a supposedly nonmagnetic osmium oxide
• Phase transition preceding magnetic long-range order in the double perovskite Ba2NaOsO6
• Spin-orbit-lattice entangled state in A${}_2$MgReO${}_6$ (A = Ca, Sr, Ba) revealed by resonant inelastic X-ray scattering
• Possible quadrupole order in tetragonal Ba2CdReO6 and chemical trend in the ground states of 5d1 double perovskites
• Vibronic order and emergent magnetism in cubic $d^1$ double perovskites
• Persistent large anisotropic magnetoresistance and insulator to metal transition in spin-orbit coupled antiferromagnets Sr2(Ir1-xGax)O4
• Electronic structure of the frustrated diamond lattice magnet NiRh${}_2$O${}_4$
• Dynamic Jahn-Teller Phenomena in Heavy Transition Metal Compounds
• Coupled-cluster approach to vibronic effects in resonant inelastic x-ray scattering of quantum materials: Application to a $5d^1$ rhenium oxide