Effect of Diffused Hydrogen on the Conductance of Fe/Mgo/Fe Magnetic   Tunnel Junctions: Atomistic Simulation
  In this work we have analysed the deterimental effect on conductance caused by diffusion of hydrogen atoms in interstitial voids during fabrication process of magnesium oxide barrier of an Fe MgO Fe magnetic tunnel junction, using first principle calculations. This diffusion of hydrogen atoms in interstitial voids in barrier disturbs a certain kind of symmetry possessed by magnesium oxide often termed as delta 1 state symmetry. Distortion in delta 1 state symmetry tempers the condutance through the magnetic tunnel junction specially in parallel configuration, which in turn reduces the Tunnelling Magneto Resistance TMR to large extent. Improved methods of fabrication can be used to counter such kind of problems which affect device operation. 
Ankit kumar verma and Bahniman Ghosh
cond-mat.mes-hall cond-mat.mtrl-sci