Electric-field tunable magnetic-field-sensor based on CoFeB/MgO magnetic tunnel junction

摘要

We demonstrate an electric-field-tunable magnetic-field-sensor based on CoFeB/MgO magnetic tunnel junction with interfacial perpendicular magnetic anisotropy (PMA). From the dynamic lock-in measurements, we show that an applied electric-field induces a peak in sensor voltage (VSENSOR) around the free layer magnetization switching regime in response to external a.c. magnetic field. Detailed measurements of VSENSOR as functions of free layer thickness, a.c. magnetic field amplitude and frequency reveal that the sensitivity of the sensor can be up to 80.8 V cm−1 Oe−1 under −0.5 V, which can be controlled by the strength and polarity of the applied electric-field via electric-field controlled PMA. We discuss the origin of our observations based on the oscillations in the tunnel magnetoresistance, and this may trigger the development of magnetoelectrically controlled magnetic-field-sensor based on magnetic tunnel junctions.