2-Axis Magnetometers Based on Full Wheatstone Bridges Incorporating Magnetic Tunnel Junctions Connected in Series.

Full Wheatstone Bridge incorporating a serially connected ensemble of Magnetic tunnel junctions was produced, targeting an application as a magnetic field compass. To that end, MTJs with RxA\sim 10\ k\Omega\ \mum^2, TMR\sim 150–200%, Hf=5\ Oe and Hf=5\ Oe were produced. In order to achieve a full bridge signal, two stacks with an asymmetric SAF reference structure where used to produce MTJs with opposite dR/dH upon annealing in the same substrate. The resulting Bridges exhibit sensitivities between 13.5–32 mV/V/Oe depending on the field range and provide a significantly advantageous alternative to AMR and GMR based bridges. [ABSTRACT FROM PUBLISHER]