Photoemission Studies of Local Reconstruction on NiSi sub 2 (111)

NiSi sub 2 is an important material that has been studied both theoretically and experimentally, and it has been assumed to have a bulk-terminated (111) surface structure. We present high resolution synchrotron-radiation photoemission and scanning tunneling microscopy(STM) results that show evidence for a local reconstruction involving adatom-triad features in contradiction to previous models for NiSi sub 2 (111). Photoemission lineshape analysis gives evidence for four near-surface components: the strongest has ~1 monolayer(mL) intensity, and the weakest has ~0.1 mL intensity, which we associate with surface adatoms.