A pr 2 00 3 The Symmetry of Magnetic Quantum Tunneling in Single Molecule Magnet Mn 12 - acetate
نویسندگان
چکیده
The symmetry of magnetic quantum tunneling (MQT) has been studied in the prototype single molecule magnet (SMM) Mn12-acetate using a micro-Hall effect magnetometer and superconducting high field vector magnet system. An average crystal 4-fold symmetry is shown to be due to local molecular environments of 2-fold symmetry that are rotated by 90 degrees with respect to one another, confirming that disorder which lowers the molecule symmetry is at the origin of MQT. We have magnetically distilled a SMM crystal to study a subset of these lower (2-fold) site symmetry molecules and present evidence for a Berry phase effect consistent with a local 2-fold symmetry. Typeset using REVTEX
منابع مشابه
Definitive spectroscopic determination of the transverse interactions responsible for the magnetic quantum tunneling in Mn(12)-acetate.
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 Mn(12)-acetate. A clear fourfold variation in the resonance positions may be attributed to an intrinsic fourth-order transverse anisotropy (O(4)/(4)). Meanwhile, a fourfold variation of the EPR line shapes confirms a recently prop...
متن کاملSymmetry of magnetic quantum tunneling in single molecule magnet Mn12-acetate.
The symmetry of magnetic quantum tunneling has been studied in the prototype single molecule magnet Mn12-acetate using a micro-Hall effect magnetometer and superconducting high field vector magnet system. An average crystal fourfold symmetry is shown to be due to local molecular environments of twofold symmetry that are rotated by 90 degrees with respect to one another, confirming that disorder...
متن کاملMagnetic quantum tunneling: insights from simple molecule-based magnets.
This perspectives article takes a broad view of the current understanding of magnetic bistability and magnetic quantum tunneling in single-molecule magnets (SMMs), focusing on three families of relatively simple, low-nuclearity transition metal clusters: spin S = 4 Ni(II)(4), Mn(III)(3) (S = 2 and 6) and Mn(III)(6) (S = 4 and 12). The Mn(III) complexes are related by the fact that they contain ...
متن کاملJ ul 2 00 3 Electronic , magnetic , and vibrational properties of the molecular magnet Mn 4 monomer and dimer
A new type of the single-molecule magnet [Mn4O3Cl4(O2CEt)3(py)3] forms dimers. Recent magnetic hysteresis measurements on this single-molecular magnet revealed interesting phenomena: an absence of quantum tunneling at zero magnetic field and tunneling before magnetic field reversal. This is attributed to a significant antiferromagnetic exchange interaction between different monomers. To investi...
متن کاملThe quantum magnetism of individual manganese-12-acetate molecular magnets anchored at surfaces.
The high intrinsic spin and long spin relaxation time of manganese-12-acetate (Mn(12)) makes it an archetypical single molecular magnet. While these characteristics have been measured on bulk samples, questions remain whether the magnetic properties replicate themselves in surface supported isolated molecules, a prerequisite for any application. Here we demonstrate that electrospray ion beam de...
متن کامل