Electronic flow across swift ( 100 MeV) heavy ion irradiated Fe/Si interfaces

Abstract

The current flow across Fe/Si interface devices has been studied after swift (∼100 MeV) heavy ion irradiation. The current flow has been also studied in a low magnetic field of <1 KG. It has been observed that the current flow in such devices increases substantially (by two orders of magnitude) after irradiation and shows a strong effect in the magnetic field. The current flow through the devices has been found to be temperature-independent from liquid nitrogen temperature to room temperature. The scanning electron microscopy and x-ray diffraction features show a mixed phase of iron silicide (Fe x Si y ) with an average grain size of ∼200 nm. It seems that a Fe/Fe x Si y /Fe tunnel junction is formed at the irradiated Fe/Si interface resulting in the observed features. Moreover, the magnetic interlayer coupling at the interface seems to control the effect of the magnetic field on current flow through the reacted (or mixed) interface.

Giant magnetoresistance (GMR) in swift heavy ion irradiated Fe films on c-silicon (Fe/c-Si)

“…Moreover, the I -V characteristics of the devices (figure 5) show a temperature independence and a nearly ohmic behaviour at lower voltages. In our earlier study [35] we have also shown such results.…”

“…To study the magnetotransport properties of the reacted/mixed phase, the current flow through the Fe/Si structure has been measured under a magnetic field of ∼10 kG. It is significant to observe that the current flow across the unirradiated samples does not show any change in the magnetic field whereas the irradiated devices have a significant change in the current flow across the Fe/Si interface in the presence of the magnetic field [35]. Moreover, the current flow across the Fe/Si interface which has been measured by the top and bottom electrical ohmic contacts across the device shows an increase by two orders of magnitude as compared with the unirradiated ones.…”

Ion beam induced surface and interface engineering

“…In contrast, the Fe layer gets completely mixed with Si and forms an amorphous Fe-silicide. Later, I-V study across Fe/Si interface devices after 100 MeV O 6+ ion irradiation has been studied [528]. The current flow has been also studied in a low magnetic field of <1 kG.…”

Magnetic and semiconducting nanostructures by swift heavy ion irradiation of Fe20Ni80films on Si substrates

“…Figure 2 shows I -V (versus T ) for unirradiated devices, showing a nonlinear diodic and more or less temperature independent conductivity (or resistivity). In our earlier study [7] with a similar substrate (i.e., Fe on Si), temperature independent conductivity was observed. Thus the positive temperature conductivity coefficient observed for the irradiated devices is not related to the silicon substrate, but seems related to the semiconducting interface.…”