Nuclear resonant scattering studies of electric field gradient in Fe monolayer on W(1 1 0)

We report on nuclear resonant scattering (NRS) studies of the electric field gradient (EFG) of a clean Fe monolayer on W(1 1 0) and its changes upon adsorption of residual gases. The consecutive NRS time spectra indicate a gradual tilt of the EFG main axis from perpendicular orientation for the as-prepared monolayer to the in plane one as a result of increasing adatom concentration.