Magnetoresistance of nickel nanocontacts fabricated by different methods

Abstract

Nickel nanocontacts have been fabricated by focused ion-beam (FIB) milling of e -beam patterned planar contacts, FIB milling of conical-shaped nanoperforations in a silicon nitride membrane, and nanoimprinting using an atomic force microscope. Their sizes ranged from 1 to 30 nm. Magnetoresistance of up to 3% is developed in a field of a few millitesla. This is interpreted in terms of ballistic magnetoresistance across a wide domain wall whose structure is determined by dipolar interactions at the contact. © 2006 American Institute of Physics.