The effect of strain for N2 dissociation on Fe surfaces

The effect of strain on N2 dissociation on Fe surfaces has been investigated by the use of density functional calculations (DFT). To study the strain effect we did calculations on fcc-Fe(1 1 1) surfaces with different lattice constants. These calculations show that by expanding the surface lattice constant, the barrier for the N2 dissociation is lowered. The same effect can be achieved by having a pseudomorphic Fe layer on a Ru(0 0 0 1) surface. The dissociation barrier on the strained Fe overlayer is lower than on the unperturbed bcc-Fe(1 1 0) surface by an amount given primarily by the strain in the overlayer. Calculations on another closed packed Fe surface, bcc-Fe(1 1 0) are also reported.