Hund's rule Magnetism in C60 ions?

Abstract

We investigate the occurrence of Hund's rule magnetism in C60(n+-) molecular ions, by computing the ground-state spin for all charge states n from -3 to +5. The two competing interactions, electron-vibration (e-v, including Jahn Teller, favoring low spin) and electron-electron (e-e, including Hund-rule exchange, favoring high spin), are accounted for based on previously computed ab-initio coupling parameters. Treating the ion coordinates as classical, we first calculate and classify the static Jahn-Teller distorted states for all n, inclusive of both e-v and e-e effects. We then correct the adiabatic result by including the zero-point energy lowering associated with softening of vibrations at the adiabatic Jahn-Teller minima. Our overall result is that while, like in previous investigations, low-spin states prevail in negative ions, Hund's rule high spin dominates all positive C60(n+) ions. This suggests also that Hund-rule magnetism could arise in fullerene cation-based solid state compounds, particularly those involving C60(2+).

12 pages, 2 figures, epj style

References in corpus (17)

• Strongly Correlated Superconductivity
• Electron--Vibron Interactions and Berry Phases in Charged Buckminsterfullerene: Part I
• Electron--Vibron Interactions in Charged Buckminsterfullerene: Pair Energies and Spectra (Part II)
• Non magnetic molecular Jahn-Teller Mott insulators
• Electron-vibration coupling constants in positively charged fullerene
• Direct Transition Between a Singlet Mott Insulator and a Superconductor
• Role of dynamic Jahn-Teller distortions in Na2C60 and Na2CsC60 studied by NMR
• Dynamical Jahn-Teller Effect and Berry Phase in Positively Charged Fullerene I. Basic Considerations
• Surprises in the Orbital Magnetic Moment and g-Factor of the Dynamic Jahn-Teller Ion C_{60}^-
• Sensitivity of the Mott Transition to Non-cubic Splitting of the Orbital Degeneracy: Application to NH3 K3C60
• Molecular terms, magnetic moments and optical transitions of molecular ions C60+/-
• Detection by NMR of a "local spin-gap" in quenched CsC60
• Berry Phase and Ground State Symmetry in H x h Dynamical Jahn-Teller Systems
• Exact zero-point energy shift in the $e\otimes (nE)$, $t\otimes (nH)$ many modes dynamic Jahn-Teller systems at strong coupling
• Hund's rule Magnetism in C60 ions?
• Metal-insulator transitions in systems with electron-phonon and Coulomb interactions
• Jahn-Teller distortions and excitation energies in C60(n+)

Cited by in corpus (3)

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• Hund's rule Magnetism in C60 ions?
• Low-energy excitations of a linearly Jahn-Teller coupled orbital quintet