Giant Magnetoresistance and Magneto-Thermopower in 3D Interconnected NixFe1-x/Cu Multilayered Nanowire Networks

Nanomaterials

Luc Piraux¹  Flavio Abreu Araujo¹  Nicolas Marchal¹  Tristan da Câmara Santa Clara Gomes¹ 

[1] Institute of Condensed Matter and Nanosciences, Université catholique de Louvain, Place Croix du Sud 1, 1348 Louvain-la-Neuve, Belgium;

关键词: 3D nanowire networks;    giant magnetoresistance;    spin caloritronics;    flexiblethermoelectrics;    nickel-iron alloys;   

DOI  :  10.3390/nano11051133

来源: DOAJ

【 摘 要 】

The versatility of the template-assisted electrodeposition technique to fabricate complex three-dimensional networks made of interconnected nanowires allows one to easily stack ferromagnetic and non-magnetic metallic layers along the nanowire axis. This leads to the fabrication of unique multilayered nanowire network films showing giant magnetoresistance effect in the current-perpendicular-to-plane configuration that can be reliably measured along the macroscopic in-plane direction of the films. Moreover, the system also enables reliable measurements of the analogous magneto-thermoelectric properties of the multilayered nanowire networks. Here, three-dimensional interconnected Ni${}_x$Fe${}_{1-x}$/Cu multilayered nanowire networks (with $0.60\le x\le 0.97$) are fabricated and characterized, leading to large magnetoresistance and magneto-thermopower ratios up to 17% and −25% in Ni${}_{80}$Fe${}_{20}$/Cu, respectively. A strong contrast is observed between the amplitudes of magnetoresistance and magneto-thermoelectric effects depending on the Ni content of the NiFe alloys. In particular, for the highest Ni concentrations, a strong increase in the magneto-thermoelectric effect is observed, more than a factor of 7 larger than the magnetoresistive effect for Ni${}_{97}$Fe${}_3$/Cu multilayers. This sharp increase is mainly due to an increase in the spin-dependent Seebeck coefficient from −7 V/K for the Ni${}_{60}$Fe${}_{40}$/Cu and Ni${}_{70}$Fe${}_{30}$/Cu nanowire arrays to −21 V/K for the Ni${}_{97}$Fe${}_3$/Cu nanowire array. The enhancement of the magneto-thermoelectric effect for multilayered nanowire networks based on dilute Ni alloys is promising for obtaining a flexible magnetic switch for thermoelectric generation for potential applications in heat management or logic devices using thermal energy.

【 授权许可】

Unknown