Design Study of a Bar-Type EMR Device

It is well known that extraordinary magnetoresistance (EMR) depends on the geometric parameters of the EMR device and the locations of the electrodes. In this paper, the performance of a bar-type EMR device is simulated with respect to the device geometry and electrode locations. The performance is evaluated with regards to the output sensitivity of the device, rather than the often analyzed EMR ratio, since it is more relevant than the EMR ratio for potential applications ranging from read heads to smart biomedical sensors. The results obtained with the finite element method show the dependence of the output sensitivity on the device geometry the placements of the electric contacts as well as the strength of the applied magnetic field in different configurations and allow finding the optimum parameters. Within the studied range of -1 to 1 T both IVVI and VIIV configurations show very similar behavior. For EMR sensors of high sensitivity, the results suggest that a simple two-contact device would provide the best performance replacing the conventional four-contact design.