Atomically thin epitaxial films of NaCl on germanium

Initial growth of insulating overlayers of NaCl on Ge(100) observed by scanning tunneling microscopy with atomic resolution

“…2 Up to now NaCl films of a few layers in thickness have mostly been studied by low-energy electron diffraction ͑LEED͒ by Henzler and co-workers 2,3 and Schwennike, Schimmelpfennig, and Pfnür. 6 The use of electrons as a probe is possible, as charging does not occur for thin insulating films due to rapid charge neutralization from the substrate by electron tunneling.…”

“…First, the STM data give direct and additional information about the interesting growth start of NaCl on Ge, for which the formation of a double layer ͑DL͒ of upright-standing NaCl dipoles, followed by a layer of NaCl dipoles with their axes parallel to the surface, was suggested. 2 Second, STM allows us to study the behavior of the NaCl overlayer at monoatomic ͑1.42 Å high͒ Ge steps directly. A remarkable and unique growth mode ͑''carpet mode''͒ which is a consequence of the two different lattice types of Ge and NaCl ͑diamond/fcc͒ was derived from high-resolution LEED studies on NaCl films of 3-8-DL thickness.…”

Stable and metastable phases of PTCDA on epitaxial NaCl films on Ag(100)

“…19,20 These thin epitaxial films exhibit the chemical surface properties of the respective bulk insulators, but avoid charging effects, since the electrons can tunnel into the conducting underlying substrate. [21][22][23][24][25][26] Evidently, the spectroscopy of large organic molecules on insulator surfaces is highly interesting and complementary to that on metal surfaces. One reason is that, due to the weaker interactions with the substrate compared to metals substrates, the intrinsic molecular states and the intermolecular interactions are more dominant and can be hence studied.…”

Surface structural analysis of LiF() thin films grown on Pt()

“…Previous surface structural investigations of LiF have focused on the bulk cleaved LiF(100) surface that can easily be produced in vacuum and was expected to be essentially unchanged from its bulk structure [1][2][3][4]. The ideally terminated surface has a square checkerboard lattice of coplanar alternating Li + cations and F -anions.…”