Current hysteresis due to changes in magnetization of magnetic tunnel junctions by spin-polarized current

We measured the current-voltage characteristics of magnetic tunnel junction s using novel dielectric materials -diamond-like carbon and polyimide barri ers- which have a well-controlled chemical composition. For most of our as grown samples we observed hysteresis loops which were independent of the ba rrier material chosen. Their non-reproducible shape was dependent on bias a nd external field. We ascribe the hysteresis to the existence of a dynamic change in the domain magnetization of the electrodes due to a feed-back mec hanism between the tunnel current and the magnetic structure. In an externa l magnetic field the hysteresis loops vanish, and the current-voltage chara cteristics are reproducible.