Surface alloying of Pd and Cu on Ru(0 0 0 1)

摘要: Abstract Codeposition of Pd and Cu on Ru(0 0 0 1) with total coverages varying from submonolayer to nm thickness has been carried out at temperatures 300 550 K. The effects heating the overlayers up 1250 K were studied. Besides characterization overlayer composition as a function temperature observation possible ordering, series questions is addressed. This includes conditions for alloying, related dimensionality (2- or 3-dimensions), significance order deposition. Photoelectron spectroscopy (PES) based application synchrotron radiation Mg Kα X-rays (XPS) was used obtain information electronic structure bimetallic via Ru 3d, 3d core levels 2p (XPS). Furthermore, valence band (VB) electron energy distribution curves (EDC's) measured photon 40 eV which Cooper minimum electrons. LEED establish overlayers. main findings studies are that (i) deposited x 1− 0⩽ ⩽1 coverage 1 ML, distributed in one layer dependent intermixing, (ii) bands very characteristic separated 4d alloying gives rise new features binding energies (BE's) between these bands, (iii) level shifts (CLS) correlated linearly films 2- 3-dimensions, an effect attributed different coordination numbers dimensions, (iv) depends only slightly deposition two coadsorbates T >660 (v) (1 × 1) patterns obtained ML Cu + 2 room 2 after annealing 660 indicating, combination pronounced hybridization orbitals, formation surface alloy.