Graphene is mechanically exfoliated on CaF 2 (111) under ambient conditions. We demonstrate the formation of a several monolayer thick hydration layer on the hydrophilic substrate and its response to annealing at temperatures up to 750 K in an ultra-high vacuum environment. Upon heating, water is released, however, it is impossible to remove the first layer. The initially homogeneous film separates into water-containing and water-free domains by two-dimensional Ostwald ripening. Upon severe heating, thick graphene multilayers undergo rupture, while nanoblisters confining sealed water appear on thinner sheets, capable of the storage and release of material. From modeling the dimensions of the nanoblisters, we estimate the graphene/CaF 2 (111) interfacial adhesion energy to be ± 0.33 0.13 − J m 2 , thereby viable for polymer-assisted transfer printing.

Here we demonstrate the controlled growth of Bi (110) and Bi(111) films on an (insulating) α-Al 2 O 3 (0001) substrate by surface X-ray diffraction and X-ray reflectivity using synchrotron ra- 1 arXiv:1611.04556v1 [cond-mat.mtrl-sci]

By the use of non-contact atomic force microscopy (NC-AFM) and Kelvin probe force microscopy (KPFM), we measure the local surface potential of mechanically exfoliated graphene on the prototypical insulating hydrophilic substrate of CaF 2 (111). Hydration layers confined between the graphene and the CaF 2 substrate, resulting from the graphene's preparation under ambient conditions on the hydrophilic substrate surface, are found to electronically modify the graphene as the material's electron density transfers from graphene to the hydration layer. Density functional theory (DFT) calculations predict that the first 2 to 3 water layers adjacent to the graphene hole-dope the graphene by several percent of a unit charge per unit cell.

With their low surface free energy, lead films tend to wet surfaces. However, quantum size effects (QSE) often lead to islands with distinct preferred heights. We study thin lead films on Ni(111) using low energy electron microscopy and selected area low energy electron diffraction. Indeed, the grown lead mesas show distinct evidence for QSE's. At about 526 K metastable mesas reshape into hemispheres within milliseconds, driven by a huge reduction in interfacial free energy. The underlying diffusion rate is many orders of magnitude faster than expected for lead on bulk lead.

The quantum-size effect (QSE) driven growth of Bi film structures on Ni(111) was studied in situ using low energy electron microscopy and selective area low energy electron diffraction (μLEED). Domains with a (3×3), [(3)(1)(-1)(2)], and (7×7) film structure are found with a height of 3, 5, and 7 atomic layers, respectively. A comparison of I/V-μLEED curves with tensor LEED calculations shows perfectly accommodated Fermi wavelengths, indicative that not only the quantized height, but also the film structure is driven by QSE.