2004/07/09 by Roland Bircher, Gregory Chaboussant, Andreas Sieber +2
Physics and Astronomy · #cond-mat.str-el
paper · pdf · doi:10.1103/physrevb.70.212413
published as Physical Review B 70, 212413 (2004) · 4 pages, 4 figures
arxiv created 2004/07/09 · arxiv updated 2009/12/01
A high resolution inelastic neutron scattering (INS) study of fully deuterated Mn12-acetate provides the most accurate spin Hamiltonian parameters for this prototype single molecule magnet so far. The Mn12-clusters deviate from axial symmetry, a non-zero rhombic term in the model Hamiltonian leading to excellent agreement with observed positions and intensities of the INS peaks. The following parameter set provides the best agreement with the experimental data: D=-0.0570(1) meV, B40=-2.78(7)⋅ 10-6 meV, B44=-3.2(6)⋅ 10-6 meV and |E| =6.8(15)⋅ 10-4 meV. Crystal dislocations are not the likely cause of the symmetry lowering. Rather, this study lends strong support to a recently proposed model, which is based on the presence of several molecular isomers with distinct spin Hamiltonian parameters.