title: Assessment of the anisotropy in the molecule Mn19 with a high-spin ground state S = 83/2 by 35 GHz electron paramagnetic resonance.
abstract: 35 GHz electron paramagnetic resonance experiments on a powder sample of the magnetic molecule Mn 19 with a high-spin ground state S = 83/2 are presented. At low temperatures, the data are well described by the simulated spectra for an isolated spin with a zero-field-splitting parameter D = 0.004 cm (-1), which is, in particular, positive. Hence, Mn 19 is not a single-molecule magnet; the previously observed magnetic hysteresis at ultralow temperatures is likely due to intermolecular dipolar interactions.
authors.affiliation: Physikalisches Institut, Universität Freiburg, Freiburg, Germany. oliver.waldmann@physik.uni-freiburg.de
authors.forename: Oliver
authors.initials: O
authors.lastname: Waldmann
authors.forename: Ayuk M
authors.initials: AM
authors.lastname: Ako
authors.forename: Hans U
authors.initials: HU
authors.lastname: Güdel
authors.forename: Annie K
authors.initials: AK
authors.lastname: Powell