Hybrid nanoelectronic-magnetic device with magnetoresistive core–shell Fe/FeC nanoparticles

Abstract

We propose a concept of hybrid nanoelectronic-magnetic device made of magnetic Fe–C core–shell nanoparticles deposited onto prepatterned Si (111) substrate with basic circuitry made of metallic conductive lines. The synthesis of magnetic material and the creation of nanoelectronic prepatterned interdigitated die are reported and to prove the effectiveness in devices, their magnetotransport properties are investigated. Magnetic Fe/FeC nanoparticles, 11 nm diameter, with a core–shell structure have been prepared by laser pyrolysis. Two different layouts of prepatterned interdigitated die, have been conceived using e-beam lithography, with various geometries. A range of microscopy techniques, transmission electron, scanning and optical, were employed for morphological characterization of the as-obtained structures. Magnetic and magnetotransport characterization using SQUID magnetometry has been performed onto both the core–shell nanoparticles and onto the hybrid device obtained by depositing centrifugated and dispersed core–shell nanoparticles from liquid carrier solutions. From magnetotransport measurements, it has been revealed that the hybrid device made of Fe/FeC nanosized materials on prepatterned interdigitated die exhibit a large giant magnetoresistive (GMR) effect of about 8% at 300 K. This result is promising in view of the use of such devices as arrays of nanosensors and in spintronic applications.