Magnetoresistance of Ni/NiO/Co Small Tunnel Junctions in Coulomb Blockade Regime

We report experimental results on the arrays of small (<0.01 µ m 2 ) Ni/NiO/Co tunnel junctions. At high temperatures or high bias conditions, we observed magnetoresistance due to changes in the relative orientation of magnetization of the electrodes. In the Coulomb blockade regime, magnetoresistance is bias-dependent and a large negative magnetoresistance of up to 40% was observed.