We use scanning tunneling microscopy ͑STM͒ and core and valence photoemission as well as low-energy electron diffraction to characterize recently discovered S/Cu͑111͒ surface structures that appear at low coverage below ordering temperatures of around 230 K. At even lower coverage ordered local arrangements are observed near steps and dislocations. Of the laterally extending structures one is open and honeycomb ͑hc͒ like, while three other structures ͑I,II,III͒ are more complicated. It is suggested that the structures can be explained as reordered ͑0001͒ planes of CuS. Surprisingly the open hc structure gives room for the Cu͑111͒ surface state according to photoemission and scanning tunneling spectra. Core level spectra provide support for one of the models proposed for an earlier studied room-temperature structure ͓Cu͑111͒-(ͱ7ϫͱ7)RϮ19.1°-S͔.

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Ultrathin Na films and islands on graphite realized prototype simple metal quantum wells with all valence electrons confined within boundaries well defined on the atomic scale. This is shown by angle-resolved photoemission and scanning tunneling microscopy data, which give unique information about electron dispersion, hole lifetimes, and Fermi wavelengths.

Photoemission from quantum well states show that K films can be grown nearly layer by atomic layer on a cooled graphite substrate. The data also indicate that this growth is preceded by the formation of one intercalated monolayer of K metal. The successive steps of intercalation and adsorption means that the properties are more intricate than suggested by previous results, which have established K/graphite as a prototype metal/ semimetal adsorption system.

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