Field sensing characteristics of magnetic tunnel junctions with (001) MgO tunnel barrier

Abstract

We map the magnetic field sensitivity and low-frequency 1∕f voltage noise of high magnetoresistance MgO-based magnetic tunnel junctions in an orthogonal magnetic field arrangement. Large sensitivity values of over 1%/Oe are obtained only when a sufficiently large hard-axis bias field is applied. The low-frequency voltage noise is observed to scale with the field sensitivity. The magnetic field noise map reveals that the signal-to-noise ratios of these devices get gradually better at higher hard-axis bias fields.