Influence of interface state in Fe/MgO/Fe magnetic tunnel junction system: C modified interfaces-a first principle study

Abstract

The Fe/MgO/Fe magnetic tunnel junction with C modified interfaces has been studied based on the first principle density function theory method under a finite bias voltage for thin (five layers) and thick (ten layers) MgO barriers. Positive and negative tunneling magnetic resistance (TMR) ratios are obtained as a function of the interface structure. We found that the tunneling conductance is highly nonlinear for asymmetric systems with C at one side of the barrier, and even a sign reversal of the TMR as a function of the bias was found to be in agreement with experiments.