Growth morphology of Pb films on Ni3Al(111)

K. Miśków, A. Krupski, K. Wandelt

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    Abstract

    Scanning tunnelling microscopy (STM) and Auger electron spectroscopy (AES) have been used to investigate the growth morphology of ultra-thin Pb films on the Ni3Al(111) face at room temperature. A previous study [K. Miśków and A. Krupski Appl Surf Sci 273, 2013, 554] using low-energy electron diffraction (LEED) and real time Auger intensity recording has demonstrated that an initial two-dimensional growth of the first Pb monolayer thick ‘wetting layer’ takes place. With further deposition and for T = 300 K, flat three atomic-layer-high islands are grown. Above 350 K, the Stranski–Krastanov growth mode was observed. In the current study, the analysis of STM measurements indicate and confirm that for coverage θ = 1.0 ML two-dimensional growth of the first Pb monolayer took place. Above θ > 1.0 ML, a three-dimensional growth of the Pb islands was observed with a strongly preferred atomic-scale ‘magic height (N),’ hexagonal shape and flat-tops. At coverage θ = 3.5 ML, only islands containing N = 3, 5, 7 and 11 atomic layers of Pb are observed. At the higher coverage θ = 5.5 ML, three types of regular hexagonal islands with side lengths of 25, 30 and 45 nm are observed. Furthermore, three different island adsorption configurations rotated by 10° ± 1° and 30° ± 6° with respect to each other were observed. After an annealing at T = 400 K of 5.5 ML of lead deposited at RT on the Ni3Al(111) the morphology of the surface changes. Post-anneal, islands of Pb are observed above the ‘wetting layer’ with an estimated average size and diameter of 768 nm2 ± 291 nm2 and 38.17 ± 6.56 nm and constant uniform height of two atomic layers (N = 2).
    Original languageEnglish
    Pages (from-to)71-78
    JournalVacuum
    Volume101
    DOIs
    Publication statusPublished - Mar 2014

    Keywords

    • Lead
    • Nickel
    • Aluminium
    • Alumina
    • Crystal growth
    • Thin film growth
    • Metal-metal interfaces
    • Low-index single crystal surface
    • Crystalline structure
    • Auger electron spectroscopy (AES)
    • Scanning tunnelling microscopy (STM)

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