Thermally activated switching in spin-flop tunnel junctions

Abstract

Magnetic tunnel junctions with a flux-closed sandwich replacing the single-soft layer have been proposed for increasing the magnetic stability of the junctions. Such flux-closed soft layers have two antiferromagnetic ground states and reverse by spin-flop switching. They are expected to essentially eliminate the critical issue of thermally activated reversal under half-select fields and ease the scaling of the emerging technology of magnetic random access memory. High-speed pulse measurements of such submicron spin-flop junctions performed over nine decades in time are reported here. The switching probability as a function of the pulse field amplitude and duration is analyzed to estimate the energy barrier to thermal activation. This activation energy is found to be substantially enhanced compared to the single-free layer case, and agrees well with the single-domain model prediction. © 2005 American Institute of Physics.