Spin-polarized electron tunneling across magnetic dielectric

Abstract

This letter deals with a magnetic tunnel junction having spin filtering by a magnetic barrier. We performed experiments in which a relatively strong external field rotates magnetizations of both ferromagnetic electrodes in the tunnel junction with the magnetic barrier simultaneously so that the two are always parallel to each other. The tunnel magnetoresistance induced in this way was over 16% at 300 K. The angular dependency of the tunnel current on the layer magnetizations indicates that the barrier contains antiferromagnetic oxide. To achieve the described effect the magnetic electrode of the junction was oxidized prior to forming the Al2O3 layer.