Information recording medium based on magnetic tunnel junctions

This article describes the mechanism of changes in capacitance and resistance in magnetic tunnel junctions (MTJs) upon magnetization reversal of one of the electrodes and presents the results of measurements of the tunnel magnetic resistance and tunnel magnetic capacitance in MTJs Tb22-δCo5Fe73/Pr6O11/Tb19-δCo5Fe76 with perpendicular anisotropy electrodes and in MTJs Co80Fe20/Pr6O11/Co30Fe70, where the magnetic electrodes have uniaxial anisotropy in the plane. It shows that when the magnetic electrodes in the magnetic tunnel are magnetized, a strong magnetic field gradient appears in the barrier nonmagnetic layer, which causes a spatial redistribution of the concentration of spin-polarized electrons in the magnetic metal/insulator interface region and leads to the appearance of an uneven distribution of electric charge. Such a magnetically induced charge affects the dielectric characteristics of the barrier nanolayer and leads to a change in the resistance and capacitance of MTJs. Moreover, this effect is most pronounced in tunnel magnetic contacts with magnetic electrodes that have perpendicular anisotropy. The change in resistance during magnetization reversal of MTJs Tb22-δCo5Fe73/Pr6O11/Tb19-δCo5Fe76 reached 120% and in MTJs Co80Fe20/Pr6O11/Co30Fe70, it did not exceed 40%. The change in capacitance during magnetization reversal of MTJs Tb22-δCo5Fe73/Pr6O11/Tb19-δCo5Fe76 reached values of 110%, and the change in capacitance of MTJs Co80Fe20/Pr6O11/Co30Fe70 reached values of 45%. This work also presents a construction scheme of a data carrier based on MTJs and describes the principle of recording and reading information from such a carrier.