Magnetoresistance of magnetic tunnel junctions with low barrier heights

A two-band model of free electrons in ferromagnetic electrodes is used to study the magnetoresistance of low and high barrier magnetic tunnel junctions (MTJs). It is demonstrated that tunneling magnetoresistance (TMR) and the electron current density through MTJs depend significantly on the dielectric constant of the MgO insulator and the electron current density through low barrier MTJs can be high enough to change the magnetization of a ferromagnetic electrode.