  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.
