Electronic and magneto-transport study across swift heavy ion irradiated exchange coupled Fe/NiO bilayer on Si substrate

Abstract

Low temperature electronic and magneto-transport study across Fe/NiO bilayer on Si substrate has been reported. These bilayer structures have been irradiated by swift heavy ions (~100MeV Fe7+ ions with a fluence of 5×1012ions/cm2). The electronic transport study across such bilayer (both unirradiated and irradiated) structures has shown the semiconducting nature of the interface. A significant decrease in current has been observed for the irradiated structure (as compared to unirradiated ones on the irradiation) which could be due to the irradiation induced introduction of defects/disorders in the structure. The magneto-transport study across unirradiated structure has shown the magnetic field sensitivity at low temperatures only whereas the irradiated structure has not shown any perceptible magnetic field sensitivity at low temperatures. Such observed intriguing feature of magnetic field sensitivity across the bilayer structures could be understood due to the motion of thermally assisted magnetic domain walls in the presence of external applied magnetic field. The observed high % MR could be related to spin-dependent electron scattering at the interfaces.