title: Angular-resolved magnetometry beyond triclinic crystals part II: torque magnetometry of Cp*ErCOT single-molecule magnets.
abstract: The experimental investigation of the molecular magnetic anisotropy in crystals in which the magnetic centers are symmetry related, but do not have a parallel orientation has been approached by using torque magnetometry. A single crystal of the orthorhombic organometallic Cp*ErCOT [Cp*=pentamethylcyclopentadiene anion (C5Me5(-)); COT=cyclooctatetraenedianion (C8H8(2-))] single-molecule magnet, characterized by the presence of two nonparallel families of molecules in the crystal, has been investigated above its blocking temperature. The results confirm an Ising-type anisotropy with the easy direction pointing along the pseudosymmetry axis of the complex, as previously suggested by out-of-equilibrium angular-resolved magnetometry. The use of torque magnetometry, not requiring the presence of magnetic hysteresis, proves to be even more powerful for these purposes than standard single-crystal magnetometry. Furthermore, exploiting the sensitivity and versatility of this technique, magnetic anisotropy has been investigated up to 150 K, providing additional information on the crystal-field splitting of the ground J multiplet of the Er(III) ion.
authors.affiliation: Dipartimento di Chimica Ugo Schiff, Università degli Studi di Firenze, Via della Lastruccia 3-13, 50019 Sesto Fiorentino (Italy).
authors.forename: Mauro
authors.initials: M
authors.lastname: Perfetti
authors.forename: Giuseppe
authors.initials: G
authors.lastname: Cucinotta
authors.forename: Marie-Emmanuelle
authors.initials: ME
authors.lastname: Boulon
authors.forename: Fadi
authors.initials: F
authors.lastname: El Hallak
authors.forename: Song
authors.initials: S
authors.lastname: Gao
authors.forename: Roberta
authors.initials: R
authors.lastname: Sessoli
keywords: lanthanides; magnetic anisotropy; single-molecule magnets; torque magnetometry