title: NMR-D study of the local spin dynamics and magnetic anisotropy in different nearly monodispersed ferrite nanoparticles.
abstract: We present a systematic experimental comparison of the superparamagnetic relaxation time constants obtained by means of dynamic magnetic measurements and (1)H-NMR relaxometry, on ferrite-based nanosystems with different composition, various core sizes and dispersed in different solvents. The application of a heuristic model for the relaxivity allowed a comparison between the reversal time of magnetization as seen by NMR and the results from the AC susceptibility experiments, and an estimation of fundamental microscopic properties. A good agreement between the NMR and AC results was found when fitting the AC data to a Vogel-Fulcher law. Key parameters obtained from the model have been exploited to evaluate the impact of the contribution from magnetic anisotropy to the relaxivity curves and estimate the minimum approach distance of the bulk solvent.
authors: Department of Physics E Amaldi, Università Uniroma TRE, Roma, Italy. lorenzo.bordonali@unipv.it
authors: L
authors: L
authors: Bordonali
authors: T
authors: T
authors: Kalaivani
authors: K P V
authors: KP
authors: Sabareesh
authors: C
authors: C
authors: Innocenti
authors: E
authors: E
authors: Fantechi
authors: C
authors: C
authors: Sangregorio
authors: M F
authors: MF
authors: Casula
authors: L
authors: L
authors: Lartigue
authors: J
authors: J
authors: Larionova
authors: Y
authors: Y
authors: Guari
authors: M
authors: M
authors: Corti
authors: P
authors: P
authors: Arosio
authors: A
authors: A
authors: Lascialfari
mesh_terms: D016880:Anisotropy; D005290:Ferric Compounds / Q000737:chemistry*; D009682:Magnetic Resonance Spectroscopy; D008280:Magnetics; D053768:Metal Nanoparticles / Q000737:chemistry*; D008956:Models, Chemical; D013113:Spin Labels
chemical_list: D005290:Ferric Compounds; D013113:Spin Labels; C001215:ferrite