Ab-initio modeling of effect of Boron and Phosphorus doping in CoFe/MgO Magnetic Tunnel Junctions

In this work analysis of Boron and Phosphorus doping in CoFe/MgO Magnetic Tunnel Junction has been carried out using first principle calculations. Boron and Phosphorus are doped in CoFe electrode, at electrode barrier interface and in the bulk. In case of Boron doping tunneling magnetoresistance (TMR) of magnetic tunnel junction is reduced to a much lower value when it is doped at electrode barrier interface instead of bulk. However in case of Phosphorus doping TMR is almost same as when Boron atoms are doped in the bulk of electrode. Boron atoms present at interface cause distortion in Δ₁ state symmetry which in turn tempers majority channel conductance. So prevention of Boron doping at interface or doping of Phosphorus atoms could result in the device having much higher value of TMR.