Electric field tuning of anisotropic magnetoresistance in Ni-Co/PMN-PT multiferroic heterostructure

Electric field tuning of anisotropic magnetoresistance (AMR) effect is investigated in Ni-Co/PMN-PT multiferroic heterostructure. The AMR ratio increases with the electric field when an external magnetic field is perpendicular to the applied current and decreases when the magnetic field is parallel to the current, showing anisotropic tunability of AMR due to the change of magnetization orientation induced by strain-mediated magnetoelectric coupling. A magnetic sensor with hall bar geometry is developed based on AMR effect in Ni-Co/PMN-PT heterostructure. The linear output range of the AMR sensor is enhanced by 250% with the applied electric field, and stable electrical response to the external magnetic field is demonstrated. The electrically tunable AMR effect has great potential for applications in magnetic field sensors with enhanced measurement range and sensitivity.