Definitive spectroscopic determination of the transverse interactions responsible for the magnetic quantum tunneling in Mn12-acetate

Abstract

We present detailed angle-dependent single crystal electron paramagnetic resonance (EPR) data for field rotations in the hard plane of the S=10 single molecule magnet Mn12-acetate. A clear four-fold variation in the resonance positions may be attributed to an intrinsic fourth order transverse anisotropy (O44). Meanwhile, a four-fold variation of the EPR lineshapes confirms a recently proposed model wherein disorder associated with the acetic acid of crystallization induces a locally varying quadratic (rhombic) transverse anisotropy (O22). These findings explain most aspects of the magnetic quantum tunneling observed in Mn12-acetate.

7 pages, including figures, accepted for publication in Phys. Rev. Lett

References in corpus (13)

• Quantum Computing in Molecular Magnets
• High frequency EPR spectra of a molecular nanomagnet provide a key to understand Quantum Tunneling of the Magnetization
• Low energy magnetic excitations of the Mn_{12}-acetate spin cluster observed by neutron scattering
• The origin of second-order transverse magnetic anisotropy in Mn12-acetate
• Instrumentation for Millimeter-wave Magnetoelectrodynamic Investigations of Low-Dimensional Conductors and Superconductors
• Effects of D-strain, g-strain, and dipolar interactions on EPR linewidths of the molecular magnets Fe8 and Mn12
• Detailed single crystal EPR lineshape measurements for the single molecule magnets Fe8Br and Mn12-ac
• Spin tunneling via dislocations in Mn-12 acetate crystals
• Dislocation-induced spin tunneling in Mn-12 acetate
• A Distribution of Tunnel Splittings in Mn${}_{12}$-Acetate
• Role of dipolar and exchange interactions in the positions and widths of EPR transitions for the single-molecule magnets Fe8 and Mn12
• Tunneling Splittings in Mn12-Acetate Single Crystals
• Quadratic transverse anisotropy term due to dislocations in Mn12-Ac directly obtained by EPR spectroscopy

Cited by in corpus (34)

• Magnetic Quantum Tunneling: Insights from Simple Molecule-Based Magnets
• Single-molecule Nanomagnets
• Determination of the magnetic anisotropy axes of single-molecule magnets
• Symmetry of Magnetic Quantum Tunneling in Single Molecule Magnet Mn12-acetate
• A rotating cavity for high-field angle-dependent microwave spectroscopy of low-dimensional conductors and magnets
• Exchange Interactions and High-Energy Spin States in Mn_12-acetate
• Effect of extra electrons on the exchange and magnetic anisotropy in the anionic single-molecule magnet Mn12
• Evidence for the S=9 excited state in Mn12-bromoacetate measured by electron paramagnetic resonance
• Transverse Magnetic Anisotropy in Mn12-acetate: Direct Determination by Inelastic Neutron Scattering
• Characterization of the S = 9 excited state in Fe8Br8 by Electron Paramagnetic Resonance
• Crystal lattice desolvation effects on the magnetic quantum tunneling of single-molecule magnets
• Electromagnetic radiation produced by avalanches in the magnetization reversal of Mn12-Acetate
• Second-order transverse magnetic anisotropy induced by disorders in the single-molecule magnet Mn12
• Realization of random-field dipolar Ising ferromagnetism in a molecular magnet
• Exchange-coupling constants, spin density map, and Q dependence of the inelastic neutron scattering intensity in single-molecule magnets
• Origin of the fast magnetization tunneling in the single-molecule magnet [Ni(hmp)(tBuEtOH)Cl]4
• On the anisotropy barrier reduction in fast relaxing Mn12 single-molecule magnets
• Experimental Upper Bound on Superradiance Emission from Mn12 Acetate
• Observation of a Distribution of Internal Transverse Magnetic Fields in a Mn12-Based Single Molecule Magnet
• Dynamics and thermalization of the nuclear spin bath in the single-molecule magnet Mn12-ac: test for the theory of spin tunneling
• Pure and Random-Field Quantum Criticality in the Dipolar Ising Model: Theory of $M{n}_{12}$ acetates
• Microwave emission from a crystal of molecular magnets -- The role of a resonant cavity
• Dynamics of molecular nanomagnets in time-dependent external magnetic fields: Beyond the Landau-Zener-Stückelberg model
• Low temperature microwave emission from molecular clusters
• Spin anisotropy effects in dimer single molecule magnets
• Tunneling and inversion symmetry in single-molecule magnets: the case of the Mn12 wheel molecule
• Asymmetric Lineshape due to Inhomogeneous Broadening of the Crystal-Field Transitions in Mn12ac Single Crystals
• Pulsed field studies of the magnetization reversal in molecular nanomagnets
• Collective electromagnetic relaxation in crystals of molecular magnets
• Quantum dynamics of crystals of molecular nanomagnets inside a resonant cavity
• Incommensurate Transverse Anisotropy Induced by Disorder and Spin-Orbit-Vibron Coupling in Mn12-acetate
• Transverse Field Ising Ferromagnetism in Mn${}_{12}$-acetate-MeOH
• Precision ESR Measurements of Transverse Anisotropy in the Single-molecule Magnet Ni${}_4$
• Quantum Fluctuations and Long-Range Order in Molecular Magnets