@inproceedings{SchmidtEgbersRath, author = {Schmidt, J.-R. and Egbers, Christoph and Rath, H. J.}, title = {Experiments on the isothermal flow in wide spherical gaps}, language = {en} } @misc{BraudWallanderBussetal., author = {Braud, N. and Wallander, H.J. and Buß, L. and L{\"o}fstrand, M. and Blomqvist, J. and Berschauer, C. and Rodriguez, A. Morales and Kofoed, P.M. and Resta, A. and Krisponeit, J.-O. and Schmidt, T. and Lundgren, E. and Flege, J.I. and Falta, J. and Merte, L.R.}, title = {Growth, structure, and morphology of ultra-thin tin oxide phases forming on Pt₃Sn(111) single crystals upon exposure to oxygen}, series = {Surface science}, volume = {767}, journal = {Surface science}, publisher = {Elsevier BV}, address = {Amsterdam}, issn = {0039-6028}, doi = {10.1016/j.susc.2025.122927}, pages = {1 -- 8}, abstract = {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.}, language = {en} }