Properties of low-lying excited manifolds in the Mn12 acetate

Abstract

Most experimental data on the single-molecule magnet Mn${}_{12}$ acetate have been successfully explained by the assumption that the Mn${}_{12}$ acetate has an effective ground-state spin of S=10. However, the effect of the low-lying excited manifolds caused by interactions between Mn spins has not been well understood. To investigate the features of the low-lying excited manifolds, the intramolecular exchange interactions are calculated using density-functional theory (DFT). With the calculated exchange parameters, the energy gap between the S=10 ground-state and the first excited-state manifold is calculated by diagonalization of the Heisenberg Hamiltonian. The upper limit on the energy gap is about 40.5 K which is likely to be overestimated due to incomplete treatment of the Coulomb potential within DFT. It is found that there are several S=9 low-energy excited-state manifolds above the S=10 ground-state manifold. The magnetic anisotropy barriers for the low-lying spin excitations are calculated using DFT. Based on the calculations, it is found that the anisotropy barriers for the low-lying excited manifolds are approximately the same as that for the ground-state manifold, which is applicable to other single-molecule magnets such as Mn${}_4$.

References in corpus (10)

• 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
• Effect of local Coulomb interactions on the electronic structure and exchange interactions in Mn12 magnetic molecules
• The Hamiltonian of the V${}_{15}$ Spin System from first-principles Density-Functional Calculations
• Properties of low-lying states in some high-nuclearity Mn, Fe and V clusters: Exact studies of Heisenberg models
• Many-Spin Interactions and Spin Excitations in Mn12
• Exchange couplings in the magnetic molecular cluster Mn12Ac
• Ab Initio Calculation of Spin Gap Behavior in CaV4O9
• Vibrationally induced fourth-order magnetic anisotropy and tunnel splittings in Mn_{12}
• Semiconductive and Photoconductive Properties of the Single Molecule Magnets Mn${}_{12}$-Acetate and Fe${}_8$Br${}_8$

Cited by in corpus (17)

• 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
• Strongly Correlated Electrons in the $[Ni(hmp)(ROH)X{]}_4$ Single Molecule Magnet: A DFT+U Study
• Single-ion and exchange anisotropy effects and multiferroic behavior in high-symmetry tetramer single molecule magnets
• Theory of high-symmetry tetramer single molecule magnets
• Fermi orbital self-interaction corrected electronic structure of molecules beyond local density approximation
• Exchange-coupling constants, spin density map, and Q dependence of the inelastic neutron scattering intensity in single-molecule magnets
• Effects of bonding type and interface geometry on coherent transport through the single-molecule magnet Mn12
• Electronic structure and magnetic anisotropy for nickel-based molecular magnets
• A Multiferroic Molecular Magnetic Qubit
• Correlation effects in the electronic structure of Mn${}_4$ molecular magnet
• Incommensurate Transverse Anisotropy Induced by Disorder and Spin-Orbit-Vibron Coupling in Mn12-acetate
• Exchange constants and spin dynamics in Mn12-acetate
• Low-spin ground state of the giant single-molecule magnets {Mn${}_{70}$} and {Mn${}_{84}$}
• Electrical Detection of Magnetization Switching in Single-Molecule Magnets
• Systematic determination of coupling constants in spin clusters from broken-symmetry mean-field solutions