Magnetoresistance of the ferromagnetic nanocontacts fabricated by electrodeposition

A “T” shaped micro-gap was fabricated by mechanical polishing between two Cu film electrodes on the surface of single-sided bonded copper. A nano-gap was then fabricated in the prepared micro-gap by resistance feedback controlled electroplating. Finally Ni₈₀Fe₂₀ ferromagnetic nanocontacts of several sizes were fabricated in the prepared nano-gap by resistance feedback controlled electroplating. The magnetoresistance of each Ni₈₀Fe₂₀ ferromagnetic nanocontact was not related to its size. Fabrication of the Ni₈₀Fe₂₀ ferromagnetic nanocontacts in the nano-gap can reduce the contribution of magnetostriction to the magnetoresistance. The magnetoresistance values of the Ni₈₀Fe₂₀ ferromagnetic nanocontacts were as high as those of the Ni ferromagnetic nanocontacts. This implies that the contribution of magnetostriction to the ballistic magnetoresistance of the ferromagnetic nanocontacts can be neglected. The ferromagnetic nanocontacts fabricated in this study, and in other cases, have two anisotropic interfaces on the sides of the nanocontacts. However, the magnetic field can alter the contribution of the interaction between the two anisotropic interfaces to the ballistic magnetoresistance of the ferromagnetic nanocontacts, and this effect can not be ruled out yet.