Searcharxiv⌕ Search

arXiv · cond-mat/0506486

Electronic and magnetic properties of a hexanuclear ferric wheel

Abstract

The electronic and magnetic properties of the hexanuclear ferric wheel [LiFe6(OCH3)12-(dbm)6]PF6 have been studied with all-electron Hartree-Fock and full-potential density functional calculations. The best agreement for the magnetic exchange coupling is at the level of the B3LYP hybrid functional. Surprisingly, the Hartree-Fock approximation gives the wrong sign for the exchange coupling. The local density approximation and the gradient corrected functional PBE strongly overestimate the exchange coupling due to the too large delocalization of the d-orbitals. These findings are supported by results from the Mulliken population analysis for the magnetic moments and the charge on the individual atoms.

Explore related subjects

Keep this discovery

Explore connections, maps & timelines

BibTeXRIS

H. Nieber, K. Doll, G. Zwicknagl. 2005-06-20. Electronic and magnetic properties of a hexanuclear ferric wheel. https://doi.org/10.1140/epjb%2Fe2005-00116-5

Cite the original work for its findings. Save a collection to share your selection of sources.

KEEP EXPLORING

Related papers

Current control of spin-wave transport in YIG via the $\small\mathbf{VO}_{\mathbf{2}}$ insulator-to-metal transition

Electrically reconfigurable spin-wave transport is central to realizing energy-efficient magnonic information technologies, yet existing current-driven approaches require current densities that undermine the fundamental dissipation advantage of spin-wave-based signal processing. Here, we demonstrate low-power electrical control of spin-wave propagation in a hybrid magnonic device comprising a low-damping yttrium iron garnet (YIG) film coupled to an adjacent vanadium dioxide ($\small\text{VO}_{2}$) stripe. Passing a small current through $\small\text{VO}_{2}$ triggers its insulator-to-metal transition (IMT), producing a sharp, reversible resistivity reduction exceeding three orders of magnitude. This abrupt phase transition locally modifies the spin-wave dispersion in YIG, reducing the group velocity and suppressing transmission by up to 40 dB near the ferromagnetic resonance frequency. Pulsed current excitation enables reconfiguration of spin-wave transport on a 10 ms timescale. Temperature-dependent measurements, corroborated by thermal modeling, decouple the respective contributions of current-induced heating of YIG and the IMT in $\small\text{VO}_{2}$, establishing the latter as the dominant control mechanism. Our results demonstrate that electrically induced phase transitions in correlated oxides constitute an energy-efficient strategy for dynamic spin-wave manipulation, providing a scalable route toward reconfigurable magnonic devices.

cond-mat.other↗

Galilean electrodynamics fluctuation in a superfluid: from general coordinate invariance to Tkachenko mode

We explore coupling the Galilean electrodynamics (GED) to an s-wave superfluid. Governed by the general coordinate invariance, the proposed effective Lagrangian hosts an unconventional superfluid whose mass is shifted by the GED gauge multiplet. We compute its electromagnetic and gravitational responses in the linear regime. In the long-wavelength limit, we discover a vanishing pressure response, and remarkably the collective mode assumes a quadratic dispersion relation reminiscent of the Tkachenko mode in an oscillating vortex lattice in (2+1) dimensions. We further demonstrate that the soft sector of the vortex lattice model is a GED in disguise, and illustrate the relation between the gauge multiplet and the Lifshitz scalar in the lowest-Landau-level regime of the vortex lattice.

cond-mat.other↗

Synchronization and Spatiotemporal Phases in Driven Precessing Domain Walls

The dynamics of extended magnetic domain walls driven by constant and alternating magnetic fields are studied using a collective coordinate $u$-$ϕ$ model. While purely constant-field driven systems exhibit deterministic spatiotemporal chaos and roughening, the alternating component can lock the precessional frequency via Shapiro-like steps. Using linear stability analysis and Floquet theory, the phase boundaries of stable, synchronized flat wall states are mapped. By studying the nonlinear dynamics of the extended system, a rich phase diagram is identified, composed of five dynamical regimes characterized by the combination of domain wall spatial order (flat, rough, or periodic) and domain wall precession temporal order (pinned, synchronized, or unsynchronized). Notably, the macroscopic temporal order of the synchronized phases can lead to a flat domain wall or to a periodic structure dominated by a narrow band of linearly unstable modes, both with coherent precession of the domain wall magnetization, while unsynchronized phases can be flat, with coherent precession, or rough with spatiotemporal chaos and incoherent precession.

cond-mat.other↗