Amoza Dávila, MartínMaxwell Villacorta, Lindley AndrésAliaga-Alcalde, NúriaGómez Coca, SilviaRuiz Sabín, Eliseo2023-03-142023-03-142021-09-280947-6539https://hdl.handle.net/2445/195270We report the spin dynamic properties of non-substituted ferrocenium complexes. Ferrocenium shows a field-induced single-molecule magnet behaviour in DMF solution while cobaltocene lacks slow spin relaxation neither in powder nor in solution. Multireference quantum mechanical calculations give a non-Aufbau orbital occupation for ferrocenium with small first excitation energy that agrees with the relatively large measured magnetic anisotropy for a transition metal S=1/2 system. The analysis of the spin relaxation shows an important participation of quantum tunnelling, Raman, direct and local-mode mechanisms which depend on temperature and the external field conditions. The calculation of spin-phonon coupling constants for the vibrational modes shows that the first vibrational mode, despite having a low spin-phonon constant, is the most efficient process for the spin relaxation at low temperatures. In such conditions, vibrational modes with higher spin-phonon coupling constants are not populated. Additionally, the vibrational energy of this first mode is in excellent agreement with the experimental fitted value obtained from the local-mode mechanism.8 p.application/pdfengcc-by-nc-nd (c) Amoza, Martín et al., 2021http://creativecommons.org/licenses/by-nc-nd/3.0/es/Propietats magnètiquesFononsFerromagnetismeMagnetic propertiesPhononsFerromagnetisminfo:eu-repo/semantics/article7187842023-03-14info:eu-repo/semantics/openAccess