TY - CHAP A1 - Schmidt, J.-R. A1 - Egbers, Christoph A1 - Rath, H. J. T1 - Experiments on the isothermal flow in wide spherical gaps Y1 - 2001 ER - TY - GEN A1 - Braud, N. A1 - Wallander, H.J. A1 - Buß, L. A1 - Löfstrand, M. A1 - Blomqvist, J. A1 - Berschauer, C. A1 - Rodriguez, A. Morales A1 - Kofoed, P.M. A1 - Resta, A. A1 - Krisponeit, J.-O. A1 - Schmidt, T. A1 - Lundgren, E. A1 - Flege, J.I. A1 - Falta, J. A1 - Merte, L.R. T1 - Growth, structure, and morphology of ultra-thin tin oxide phases forming on Pt₃Sn(111) single crystals upon exposure to oxygen T2 - Surface science N2 - Here we report an investigation of ultrathin tin oxide films on Pt3Sn(111) using low-energy electron microscopy (LEEM), microspot low-energy electron diffraction (𝜇-LEED), scanning tunneling microscopy (STM), surface X-ray diffraction (SXRD), and high-resolution X-ray photoelectron spectroscopy (XPS). Oxidation at ∼390–410 ◦C produces triangular, two-dimensional oxide islands that nucleate rapidly and exhibit self-limited lateral growth, attributed to limited Sn diffusion from the subsurface of the crystal. 𝜇-LEED shows that the initially formed (4 × 4) Sn oxide is subsequently converted to a more oxygen-rich (2 × 2𝑛) ‘‘stripe’’ phase. At 630 ◦C, enhanced Sn mobility enables a closed (4 × 4) film. The (2 × 2𝑛) phase is shown to consist of a (2 × 2) Sn lattice modulated by 1D stripe defects with spacings of 𝑛 = 4–6 atomic rows; LEED and SXRD measurements show diffraction features corresponding to this striped superstructure. The two oxides can be distinguished in XPS by their O 1s lineshapes: the (4 × 4) phase shows a clear doublet attributable to distinct O species, whereas the (2 × 2𝑛) phase exhibits a broader envelope consistent with a distribution of O coordination environments. The Sn 3d5∕2 spectra are similar for both phases, reflecting closely related Sn bonding motifs. The spectra are consistent with those of previous near-ambient-pressure XPS measurements, suggesting that the surface oxides forming under CO oxidation conditions are similar to those studied here. KW - Tin oxide KW - Platinum-tin KW - LEEM KW - STM KW - SnOx KW - SXRD Y1 - 2026 U6 - https://doi.org/10.1016/j.susc.2025.122927 SN - 0039-6028 SN - 1879-2758 VL - 767 SP - 1 EP - 8 PB - Elsevier BV CY - Amsterdam ER -