Nano-contact microscopy of supracrystals

• Adam Sweetman,
• Nicolas Goubet,
• Ioannis Lekkas,
• Marie Paule Pileni and
• Philip Moriarty

Beilstein J. Nanotechnol. 2015, 6, 1229–1236, doi:10.3762/bjnano.6.126

• tunnelling microscopy and spectroscopy. Keywords: dynamic force microscopy; nanoparticle; non-contact atomic force microscopy; point contact imaging; scanning probe microscopy; supracrystal; Introduction Artificial solids comprising extended assemblies of nanocrystals with a narrow size distribution

• etched tungsten wire glued to one tine of the tuning fork were first prepared on clean Si(111)-(7 × 7) samples by standard STM techniques before imaging of the nanocrystal samples. During imaging of the supracrystal surface, spontaneous and regular tip changes were observed, thus it is possible that the

• changes during scanning. As such, we cannot assume a priori that a simple single atom “point-like” contact is responsible for the observed contrast. Finally, the supracrystal is composed of a mixture of single domain and polycrystalline nanocrystals [40], complicating the analysis of the DFM images. We