Kinetics and the crystallographic structure ofbismuth during liquefaction and solidification on an insulating substrate

Here we study the kinetics of liquefaction and solidification of thin bismuth films grown on an insulating substrate by pulsed laser deposition (PLD) and molecular beam epitaxy (MBE) and investigated by in situ electron and X-ray diffraction. By PLD, we can grow films similar to those obtained using MBE, studied by ex-situ AFM, KPFM, XRR, and XRD. The liquefaction-solidification transition is monitored in real-time by RHEED and synchrotron XRD, observing thereby the dewetting phenomenon and the formation of spherical droplets which size depends on the initial film thickness. Studying this phase transition in more detail, we find abrupt liquefaction and solidification, resulting in formation of the nanodots oriented with the (110) crystallographic plane parallel to the substrate. Furthermore, by analysis of the recorded specular diffraction rods, we propose growth by initial deposition, followed by a transformation into nandots, followed by further deposition. Overall, we demonstrate that controlling the growth scenario for Bi nanostructures, here shown by PLD and MBE, one is able to steer its resulting shape, size and corresponding (materials) properties.