COMPARATIVE PHOTOEMISSION-STUDY OF PT(111)(ROOT-3-X-ROOT-3)R30-DEGREES CE AND PT(111)(2X2) LA

Careful examination of the low-energy electron diffraction image from Pt(111)(root 3x root 3) R30 degrees Ce shows the designation to be onl y approximate and suggests a close structural similarity to Pt(111)(2x 2)La. This is backed up by angle-resolved photoemission spectroscopy, which reveals the valence-band structure of the two alloys to be remar kably similar. The use of the La alloy to identify the non-f features in the photoemission spectra of Pt(111)(root 3x root 3)R30 degrees Ce is thus put on a firm footing. The Kondo peak in He II angle-resolved ultraviolet photoemission spectroscopy data of Pt(111)(root 3x root 3) R30 degrees Ce is observed at the first and second fi points, suggest ing the presence of surface umklapp scattering. [S0163-1829(98)10039-5 ].