First-Principle Study of Effects of Magnesium Oxide Adsorption in SiCNT-Based Magnetic Tunnel Junction

Abstract

We attempt to study the spin-dependent transport properties of a magnetic tunnel junction (MTJ) which consists of a magnesium oxide (MgO)-adsorbed SiCNT tunnel barrier in between two half-metallic ferromagnetic (HMF) CrO2 electrodes. The I–V characteristic curves for both parallel and anti-parallel magnetization states are obtained. The comparison of the results with other reported studies suggests that a very large value of tunnel magneto-resistance (TMR) and a perfect spin filtration is obtained majorly due to the adsorption of MgO molecules and also due to the use of HMF electrodes. For bias voltages above 0.4 V, a high TMR at ∼100% is obtained. The TMR is also high at ∼97.89% for lower bias voltages. Also, a perfect spin filtration of almost 100% is obtained at all bias voltages. These results suggest that this device can prove to be of significant use in spin valves, MRAMs, and other spintronics applications. The spin-dependent non-equilibrium transport properties are also investigated by analyzing the bias-dependent transmission coefficients.