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MA: Fachverband Magnetismus
MA 23: Poster Magnetism I
MA 23.20: Poster
Tuesday, March 28, 2023, 17:00–19:00, P1
Single Molecule Magnets based on dimetallofullerenes — •Matheus Barbosa, Wei Yang, Fupin Liu, and Alexey Popov — Leibniz Institute for Solid State and Materials Research - Dresden, Germany
Dimetallofullerenes are compounds with metal-metal bonds encapsulated in fullerene cages, recognized as good Single Molecule Magnets (SMMs). In the last years, molecules based on Terbium (Tb) and Dysprosium (Dy) have been demonstrating high potential applicability owing to the strong ferromagnetic coupling of 4f-electrons and trapped valence electron of the bond between them. Their static and dynamic properties are under investigation and have showed high blocking temperatures of magnetization, giant coercive fields and complexes relaxation processes. Dy-Dy dimer inside the fullerene cage C80 (Dy2@C80) shows different magnetic behavior depending on the chosen stabilizing chemical groups. In comparation, for Dy2@C80(CF3) the susceptibility χm per temperature (ZFC-FC curves) is observed to be double-peak below 21 K, with the shape dependent of the temperature and field sweep rates, in contrast to Dy2@C80(CH2C6H5). The estimated energy barrier (613 K for {Dy2}−CF3 and 615 K for {Dy2}−CH2C6H5) and the ferromagnetic coupling constant have the similar values. However, at low temperature in zero magnetic field (QTM regime) the relaxation rate is c.a. 10 times faster for {Dy2}−CF3 than for the {Dy2}−CH2C6H5. Dilution studies demonstrated that this difference does not depend on the intermolecular interactions and should be ascribed to a different influence of the exohedral group.