From ballistic transport to tunneling in electromigrated ferromagnetic breakjunctions

Abstract

We fabricate ferromagnetic nanowires with constrictions whose cross section can be reduced gradually from 100 nm to the atomic scale and eventually to the tunneling regime by means of electromigration. These devices are mechanically stable against magnetostriction and magnetostatic effects. We measure magnetoresistances ~ 0.3% for 100*30 nm^2 constrictions, increasing to a maximum of 80% for atomic-scale widths. These results are consistent with a geometrically-constrained domain wall trapped at the constriction. For the devices in the tunneling regime we observe large fluctuations in MR, between -10 and 85%.

4 pages, 5 figures

References in corpus (5)

• Quantum properties of atomic-sized conductors
• Controlled Fabrication of Nanogaps in Ambient Environment for Molecular Electronics
• Kondo Effect in Electromigrated Gold Break Junctions
• Magnetic and orbital blocking in Ni nanocontacts
• Inverse Tunneling Magnetoresistance in nanoscale Magnetic Tunnel Junctions

Cited by in corpus (13)

• Dynamical Mean-Field Theory for Molecular Electronics: Electronic Structure and Transport Properties
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• Kondo effect and conductance of nanocontacts with magnetic impurities
• Theoretical study of the conductance of ferromagnetic atomic-sized contacts
• Anisotropic magnetoresistance in nanocontacts
• The nature of the electrical conduction in ferromagnetic atomic-size contacts: insights from shot noise measurements and theoretical simulations
• Emergence of half-metallicity in suspended NiO chains
• The Origin of Tunneling Anisotropic Magnetoresistance in Break Junctions
• Domain-wall induced large magnetoresistance effects at zero applied field in ballistic nanocontacts
• Dzyaloshinskii-Moriya interaction in transport through single molecule transistors
• Transport Properties of an Interacting Quantum Dot with a Non-Uniform Magnetization
• Formation and anisotropic magnetoresistance of Co/Pt nano-contacts through aluminum oxide barrier
• Controlled Electrode Magnetization Alignment in Planar Elliptical Ferromagnetic Break Junction Devices