β Scribed by J. M. Heras; L. Viscido; G. Wedler; D. Borgmann
No coin nor oath required. For personal study only.
The growth of Pd layers on polycrystalline Cu substrate at 176 K and 300 K was studied in an Auger system with facilities for photoelectric work function (WF) measurements and automated data acquisition. The LVV and MVV Auger transitions of Cu, as well as the corresponding MVV and NVV of Pd, were monitored in relation to Pd overlayer thickness, annealing temperature and sputtering time. The βlocalβ WF change, determined through the secondaries' cutβoff shift, and the absolute photoelectric WF were also monitored.
The initially linear increase in the Pd atom fraction, with only one break during deposition at 300 K, suggests a StranskiβKrastanov film growth mechanism. The simultaneously monitored Auger M~23~M~45~M~45~ Cu doublet at 59β61 eV changes from the very beginning of the Pd deposition into one broadened peak at 61 eV, possibly owing to a roughness effect. With sputtering, the slope of the Pd concentration at the interface decreases when the temperature of deposition and sputtering increases from 176 K to 300 K, indicating diffusion of Pd even at 300 K. By sputtering with Ar^+^ ions of 5 keV, a depth resolution of βΌ3.2 nm was found. Annealing at T > 473 K causes a rapid diffusion of Pd atoms into the Cu substrate.
The βlocalβ WF is affected dramatically by Pd deposition and sputtering, while the average photoelectric WF is not as sensitive.
π SIMILAR VOLUMES
The underpotential deposition of copper on (100) and (111) palladium single crystals and polycrystalline substrates was investigated voltammetrically. Charge values indicate that the adsorption process leads to the formation ofa first monolayer which follows the substrateorientation. On the (100) pl