Magnetism and magnetoresistance of single Ni-Cu alloy nanowires.

Andreea Costas,Maria Eugenia Toimil-Molares,Ionel Stavarache,Andrei Kuncser,Camelia Florica,Ionut Enculescu,Victor Kuncser,Elena Matei

doi:10.3762/bjnano.9.219

Andreea Costas, Maria Eugenia Toimil-Molares + Show 6 more

Open Access

https://doi.org/10.3762/bjnano.9.219

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Abstract

Arrays of magnetic Ni–Cu alloy nanowires with different compositions were prepared by a template-replication technique using electrochemical deposition into polycarbonate nanoporous membranes. Photolithography was employed for obtaining interdigitated metallic electrode systems of Ti/Au onto SiO2/Si substrates and subsequent electron beam lithography was used for contacting single nanowires in order to investigate their galvano-magnetic properties. The results of the magnetoresistance measurements made on single Ni–Cu alloy nanowires of different compositions have been reported and discussed in detail. A direct methodology for transforming the magnetoresistance data into the corresponding magnetic hysteresis loops was proposed, opening new possibilities for an easy magnetic investigation of single magnetic nanowires in the peculiar cases of Stoner–Wohlfarth-like magnetization reversal mechanisms. The magnetic parameters of single Ni–Cu nanowires of different Ni content have been estimated and discussed by the interpretation of the as derived magnetic hysteresis loops via micromagnetic modeling. It has been theoretically proven that the proposed methodology can be applied over a large range of nanowire diameters if the measurement geometry is suitably chosen.

Highlights

Nowadays, due to the continuous search for new electronic devices that exploit specific properties of nanostructures, the methods of controlled fabrication are in the spotlight of researchers
In this paper we report on a strategy of studying the magnetic properties of single Ni–Cu alloy nanowires of high aspect ratio via specific anisotropic magnetoresistance measurements
scanning electron microscope (SEM) micrographs of arrays of Ni–Cu alloy nanowires show that the nanowires obtained at all four different electrodeposition potentials have a regular cylindrical shape with smooth walls along their entire 30 μm length and an average diameter of about 100 nm

Summary

Introduction

Due to the continuous search for new electronic devices that exploit specific properties of nanostructures, the methods of controlled fabrication are in the spotlight of researchers. In this paper we report on a strategy of studying the magnetic properties of single Ni–Cu alloy nanowires of high aspect ratio via specific anisotropic magnetoresistance measurements.

Results

Conclusion