Femtosecond pulsed laser deposition (fs-PLD) in vacuum has been demonstrated to be a powerful and versatile tool for the production of metal and semiconductor nanoparticle-assembled films. In contrast to ablation with longer laser pulses, namely ns-PLD, where the presence of a high-pressure gas is necessary to obtain nanoparticles (NPs), in fs-PLD the NPs are produced under vacuum as a consequence of decomposition of a target material irradiated by fs pulses. The nanoparticle-assembled films show a structure with agglomerates of NPs, each one formed by closely connected NPs with a significant shape and orientation anisotropy and negligible coalescence, even at high NP volume fractions, though the precise nature of the interface remains uncertain, and an exchange interaction is active among the nearest NPs. The as-deposited mono-component (Fe, Co, Ni,) and bi-component (NiSi, CoCu, FeAg) magnetic films present a high in-plane remanence ratio, relatively low values of the saturation and coercive fields and a steep slope near coercivity. This appears related to the fact that the nanoparticles, coupled by exchange interactions, are effectively single domain and single grain NPs, as observed comparing AFM and X-Ray size evaluations. Furthermore, the exchange interaction between hard magnetic nanoparticles (Terfenol-D) and soft magnetic nanoparticles (Iron) is active in the fs-PLD film, giving a cumulative magnetic response resulting from an average of the properties of the two component phase (exchange-spring magnets). In prospective the striking properties of these nanoparticle-assembled films appear very promising for potential application as nanocomposite permanent magnets and in data storage technology. Finally, the influence of the novel structural conditions on the coupling between strain and magnetization, and/or strain and resistivity, in Co50Fe50 NP films deposited on Kapton substrate, was investigated, thus evidencing novel elastoresistive and elastomagnetic functionalities and evaluating their relative sensitivities.

Magnetic, Elastomagnetic and Elastoresistive Behaviour of Nanoparticle-Assembled Films Produced by fs-PLD / Iannotti, Vincenzo; Amoruso, Salvatore; Ausanio, Giovanni; Campana, C.; Esposito, E.; Hison, C.; Pagliarulo, V.; Pepe, G.; Lanotte, L.. - Unico:(2010), pp. 69-72. (Intervento presentato al convegno 7th International Workshop on Functional and Nanostructured Materials (FNMA’10) tenutosi a The Palace Hotel, Sliema, Malta nel 16-20 July 2010).

Magnetic, Elastomagnetic and Elastoresistive Behaviour of Nanoparticle-Assembled Films Produced by fs-PLD

IANNOTTI, VINCENZO;AMORUSO, SALVATORE;AUSANIO, GIOVANNI;G. Pepe;
2010

Abstract

Femtosecond pulsed laser deposition (fs-PLD) in vacuum has been demonstrated to be a powerful and versatile tool for the production of metal and semiconductor nanoparticle-assembled films. In contrast to ablation with longer laser pulses, namely ns-PLD, where the presence of a high-pressure gas is necessary to obtain nanoparticles (NPs), in fs-PLD the NPs are produced under vacuum as a consequence of decomposition of a target material irradiated by fs pulses. The nanoparticle-assembled films show a structure with agglomerates of NPs, each one formed by closely connected NPs with a significant shape and orientation anisotropy and negligible coalescence, even at high NP volume fractions, though the precise nature of the interface remains uncertain, and an exchange interaction is active among the nearest NPs. The as-deposited mono-component (Fe, Co, Ni,) and bi-component (NiSi, CoCu, FeAg) magnetic films present a high in-plane remanence ratio, relatively low values of the saturation and coercive fields and a steep slope near coercivity. This appears related to the fact that the nanoparticles, coupled by exchange interactions, are effectively single domain and single grain NPs, as observed comparing AFM and X-Ray size evaluations. Furthermore, the exchange interaction between hard magnetic nanoparticles (Terfenol-D) and soft magnetic nanoparticles (Iron) is active in the fs-PLD film, giving a cumulative magnetic response resulting from an average of the properties of the two component phase (exchange-spring magnets). In prospective the striking properties of these nanoparticle-assembled films appear very promising for potential application as nanocomposite permanent magnets and in data storage technology. Finally, the influence of the novel structural conditions on the coupling between strain and magnetization, and/or strain and resistivity, in Co50Fe50 NP films deposited on Kapton substrate, was investigated, thus evidencing novel elastoresistive and elastomagnetic functionalities and evaluating their relative sensitivities.
2010
9788393054916
Magnetic, Elastomagnetic and Elastoresistive Behaviour of Nanoparticle-Assembled Films Produced by fs-PLD / Iannotti, Vincenzo; Amoruso, Salvatore; Ausanio, Giovanni; Campana, C.; Esposito, E.; Hison, C.; Pagliarulo, V.; Pepe, G.; Lanotte, L.. - Unico:(2010), pp. 69-72. (Intervento presentato al convegno 7th International Workshop on Functional and Nanostructured Materials (FNMA’10) tenutosi a The Palace Hotel, Sliema, Malta nel 16-20 July 2010).
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Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/11588/495177
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