MAGNETORESISTANCE AND MAGNETIC-PROPERTIES OF NIFE OXIDE/CO JUNCTIONS PREPARED BY MAGNETRON SPUTTERING/

NiFe/oxide/Co junctions were fabricated by magnetron sputtering for st udies of polarized electron transport across the insulating barrier. A l2O3, Al-Al2O3, and MgO insulating barriers were prepared with junctio n resistances from 0.5 to 116 Omega. The I-V characteristics at room t emperature are linear. For low barrier resistance, the magnetoresistan ce of the structure is dominated by the anisotropic magnetoresistance of the ferromagnetic electrodes. For the higher barrier resistances, a different magnetoresistance effect is observed, which is tentatively related to tunneling or spin-valve effects across the insulating junct ion.