Atomic and local electronic structure of Gd thin films studied by STM and STS

Abstract

We report on combined scanning tunneling microscopy and spectroscopy studies of the atomic and local electronic structure of Gd thin films on W(110) in the submonolayer coverage regime. The tunneling spectra of a recent (8\ifmmode\times\else\texttimes\fi{}2), and the previously known (7\ifmmode\times\else\texttimes\fi{}2), (6\ifmmode\times\else\texttimes\fi{}2), (5\ifmmode\times\else\texttimes\fi{}2) and $c(5\ifmmode\times\else\texttimes\fi{}3)$ superstructures show significant differences in the local electronic structure, which were found to be due to the varying interatomic distances within the Gd film. Spatially resolved maps of the tunneling barrier height reveal a nonmonotonic behavior of the local work function from the open (8\ifmmode\times\else\texttimes\fi{}2) structure to the close-packed first monolayer.