One-dimensional atomic and electronic structures of submonolayer potassium deposited on stepped Ni(7Â 5Â 5) surface

We deposited 0.01-0.16 ML (monolayer) of potassium on stepped (7 5 5) [=6(1 1 1) × (1 0 0)] surface of nickel in order to fabricate and to understand the growth process of one-dimensional (1D) potassium atomic-chain structure by observing the low-energy-electron-diffraction (LEED) patterns. The LEED patterns from potassium adsorbates exhibit a distinct coverage dependence that 1× streaks first appeared at low coverages up to 0.04 ML and later 2× streaks appeared at around 0.09 ML. The streaks become spotty at the higher coverage. We explained these coverage-dependent changes in LEED patterns in a thorough comparison with kinematically calculated LEED patterns constructing a reasonable growth model.