Publication de 12 numéros par an
ISSN Imprimer: 0040-2508
ISSN En ligne: 1943-6009
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Magnetoresistance and Spin Polarization of Electron Current in Magnetic Tunneling Junctions
RÉSUMÉ
The influence of the bias voltage on the magnetoresistance and spin polarization of the electron current of the ferromagnetic metal-insulator-ferromagnetic metal (FM/I/FM) tunneling junction has been studied theoretically a two-band model of free electrons in ferromagnetic electrodes. It is shown that the value and sign of the magnetoresistance of the FM/I/FM tunneling junction depend essentially both on the height and the width of the potential barrier and on the value of the bias voltage. It has been found that the height and the width of the potential barrier can be chosen in such a way that the value of the magnetoresistance can be both decreased and increased as the bias voltage increases. It has been determined that the magnetoresistance changes the sign and oscillates with increasing bias voltage. The change of the sign of the magnetoresistance takes place due to the fact that the tunneling transmission coefficient of the majority electrons is the largest in the case of the antiparallel magnetization of the ferromagnetic electrodes and not parallel one. It has been shown that the value and sign of the spin polarization of the electron current can be changed with reversing the ferromagnetic electrode magnetizations.