Finemet type alloys have been investigated from DC to 1 GHz at different induction levels upon different treatments: as amorphous precursors, as ribbons nanocrystallized with and without an applied saturating field, as consolidated powders. The lowest energy losses at all frequencies and maximum Snoek's product are exhibited by the transversally field-annealed ribbons. This is understood in terms of rotation-dominated magnetization process in the low-anisotropy material. Intergrain eddy currents are responsible for the fast increase of the losses with frequency and for early permeability relaxation of the powder cores. Evidence for resonant phenomena at high frequencies and for the ensuing inadequate role of the static magnetic constitutive equation of the material in solving the magnetization dynamics via the Maxwell's diffusion equation of the electromagnetic field is provided. It is demonstrated that, by taking the Landau–Lifshitz–Gilbert equation as a constitutive relation, the excellent frequency response of the transverse anisotropy ribbons can be described by analytical method.
Broadband magnetic losses of nanocrystalline ribbons and powder cores / Beatrice, Cinzia; Dobák, Samuel; Ferrara, Enzo; Fiorillo, Fausto; Ragusa, Carlo; Füzer, Ján; Kollár, Peter. - In: JOURNAL OF MAGNETISM AND MAGNETIC MATERIALS. - ISSN 0304-8853. - 420:(2016), pp. 317-323. [10.1016/j.jmmm.2016.07.045]
Broadband magnetic losses of nanocrystalline ribbons and powder cores
BEATRICE, CINZIAInvestigation
;FERRARA, ENZO;Fiorillo, Fausto;
2016
Abstract
Finemet type alloys have been investigated from DC to 1 GHz at different induction levels upon different treatments: as amorphous precursors, as ribbons nanocrystallized with and without an applied saturating field, as consolidated powders. The lowest energy losses at all frequencies and maximum Snoek's product are exhibited by the transversally field-annealed ribbons. This is understood in terms of rotation-dominated magnetization process in the low-anisotropy material. Intergrain eddy currents are responsible for the fast increase of the losses with frequency and for early permeability relaxation of the powder cores. Evidence for resonant phenomena at high frequencies and for the ensuing inadequate role of the static magnetic constitutive equation of the material in solving the magnetization dynamics via the Maxwell's diffusion equation of the electromagnetic field is provided. It is demonstrated that, by taking the Landau–Lifshitz–Gilbert equation as a constitutive relation, the excellent frequency response of the transverse anisotropy ribbons can be described by analytical method.File | Dimensione | Formato | |
---|---|---|---|
199_JMMM_2016.pdf
solo utenti autorizzati
Tipologia:
final published article (publisher’s version)
Licenza:
Non Pubblico - Accesso privato/ristretto
Dimensione
981.64 kB
Formato
Adobe PDF
|
981.64 kB | Adobe PDF | Visualizza/Apri Richiedi una copia |
J. Magn. Magn. Mater. vol. 420 (2016)_preprint.pdf
accesso aperto
Tipologia:
submitted version (author’s pre-print)
Licenza:
Pubblico - Tutti i diritti riservati
Dimensione
701.32 kB
Formato
Adobe PDF
|
701.32 kB | Adobe PDF | Visualizza/Apri |
I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.