Core level photoemission of iodine overlayers

Abstract

We report the core level binding energies of chemisorbed iodine on Fe(110) and Fe(100). A decrease of 0.6 eV in the binding energies of the iodine core levels is observed with the increasing coverage of the chemisorbed iodine overlayer. This change in core level binding energies with coverage is compared with the results for iodine overlayers on other transition metal surfaces. The difference in core level binding energies between chemisorbed iodine on Fe(110) and molecularly adsorbed iodine on Fe(110) is explained using a Born–Haber cycle and an ‘‘equivalent’’ cores approximation.