Unbiased evaluation of zero-field splitting D parameter in high-spin molecules from DC magnetic data with incomplete powder averaging

Andrea Cornia (1) , Anne-Laure Barra (2) , Giordano Poneti (3) , Erik Tancini (1) , Roberta Sessoli (4)

1 UNIMORE - Università degli Studi di Modena e Reggio Emilia = University of Modena and Reggio Emilia
2 LNCMI-G - Laboratoire national des champs magnétiques intenses - Grenoble
3 UFRJ - Universidade Federal do Rio de Janeiro [Brasil] = Federal University of Rio de Janeiro [Brazil] = Université fédérale de Rio de Janeiro [Brésil]
4 DICUS UniFI - Dipartimento di Chimica 'Ugo Schiff' [Sesto Fiorentino]

A simple scheme is presented to account for preferential orientation effects in the DC magnetic response of polycrystalline samples of anisotropic high-spin molecules, like single-molecule magnets. A single additional least-squares parameter is introduced in the fitting of isothermal magnetization vs. field data to describe the leading part of a non-spherical distribution of anisotropy axes. The procedure is shown to afford an accurate D parameter and is potentially applicable whenever complete powder averaging cannot be achieved.

Mots clés: single-molecule magnets; magnetic anisotropy; zero-field splitting; DC magnetometry; preferential orientation; high-spin molecules

Domaines: Agrégats Moléculaires et Atomiques [physics.atm-clus]

Andrea Cornia, Anne-Laure Barra, Giordano Poneti, Erik Tancini, Roberta Sessoli. Unbiased evaluation of zero-field splitting D parameter in high-spin molecules from DC magnetic data with incomplete powder averaging. Journal of Magnetism and Magnetic Materials, 2020, 510, pp.166713. ⟨10.1016/j.jmmm.2020.166713⟩. ⟨hal-02912243⟩