Crossover between Thermally Assisted and Pure Quantum Tunneling in Molecular Magnet Mn12-Acetate

Abstract

The crossover between thermally assisted and pure quantum tunneling has been studied in single crystals of high spin (S=10) uniaxial molecular magnet Mn12 using micro-Hall-effect magnetometry. Magnetic hysteresis and relaxation experiments have been used to investigate the energy levels that determine the magnetization reversal as a function of magnetic field and temperature. These experiments demonstrate that the crossover occurs in a narrow (0.1 K) or broad (1 K) temperature interval depending on the magnitude of the field transverse to the anisotropy axis.

5 pages, 4 figures

References in corpus (2)

• Answer to the comment of Chudnovsky: On the square-root time relaxation in molecular nanomagnets
• First- and second-order transitions of the escape rate in ferrimagnetic or antiferromagnetic particles

Cited by in corpus (47)

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• Spin-spin cross-relaxation in single-molecule magnets
• Single-molecule Nanomagnets
• Spin tunneling via dislocations in Mn-12 acetate crystals
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• Electronic Transport in Single-Molecule Magnets on Metallic Surfaces
• Determination of the magnetic anisotropy axes of single-molecule magnets
• Spin quantum tunneling via entangled states in a dimer of exchange coupled single-molecule magnets
• Dislocation-induced spin tunneling in Mn-12 acetate
• Symmetry of Magnetic Quantum Tunneling in Single Molecule Magnet Mn12-acetate
• Exchange Interactions and High-Energy Spin States in Mn_12-acetate
• Photon-assisted tunneling in a Fe8 Single-Molecule Magnet
• Nuclear spin dynamics in the quantum regime of a single-molecule magnet
• Quantum Step Heights in Hysteresis Loops of Molecular Magnets
• Resonant photon absorption in the low spin molecule V15
• 55Mn NMR in Mn12 acetate: Hyperfine interaction and magnetic relaxation of cluster
• Transverse Magnetic Anisotropy in Mn12-acetate: Direct Determination by Inelastic Neutron Scattering
• Magnetization Process of Single Molecule Magnets at Low Temperatures
• Quantum tunnelling of magnetization in Mn12-ac studied by 55Mn NMR
• Tunneling Splittings in Mn12-Acetate Single Crystals
• Macroscopic quantum tunneling and quantum-classical phase transitions of the escape rate in large spin systems
• 'Hole-digging' in ensembles of tunneling Molecular Magnets
• Tunneling with dissipation and decoherence for a large spin
• Semiconductive and Photoconductive Properties of the Single Molecule Magnets Mn${}_{12}$-Acetate and Fe${}_8$Br${}_8$
• Quadratic transverse anisotropy term due to dislocations in Mn12-Ac directly obtained by EPR spectroscopy
• Phonon-mediated spin-flipping mechanism in the spin ices Dy${}_2$Ti${}_2$O${}_7$ and Ho${}_2$Ti${}_2$O${}_7$
• Observation of a Distribution of Internal Transverse Magnetic Fields in a Mn12-Based Single Molecule Magnet
• Self-organized patterns of macroscopic quantum tunneling in molecular magnets
• Dynamics and thermalization of the nuclear spin bath in the single-molecule magnet Mn12-ac: test for the theory of spin tunneling
• Abrupt Transition between Thermally-Activated Relaxation and Quantum Tunneling in a Molecular Magnet
• Crystal defects and spin tunneling in single crystals of Mn12 clusters
• Level splittings in exchange-biased spin tunneling
• Quantum deflagration and supersonic fronts of tunneling in molecular magnets
• How systems of single-molecule magnets magnetize at low temperatures
• Macroscopic quantum effects generated by the acoustic wave in a molecular magnet
• Collective electromagnetic relaxation in crystals of molecular magnets
• Effect of dipolar interactions on the magnetization of a cubic array of nanomagnets
• New geometries for high spatial resolution hall probes
• Density Matrix Equation for a Bathed Small System and its Application to Molecular Magnets
• Equal-Interval Splitting of Quantum Tunneling in Single-Molecule Magnets with Identical Exchange Coupling
• Field-tuned quantum tunneling in a supramolecule dimer $[M{n}_4{]}_2$
• Macroscopic quantum tunneling of magnetization explored by quantum-first-order reversal curves (QFORC)
• Exact Activation Energy of Magnetic Single Domain Particles
• Square root relaxation: two possible mechanisms
• EPR spectrum via entangled states for an Exchange-Coupled Dimer of Single-Molecule Magnets
• Quantum Fluctuations and Long-Range Order in Molecular Magnets
• Quantum nanomagnets and nuclear spins: an overview