Mfp 3d afm system

PFM measurements were performed at room temperature using Asylum Research MFP-3D AFM system. Platinum coated Si cantilevers (Olympus OMCL-AC240TM) were used in the measurements.

The morphology of the samples was investigated employing an Asylum Research MFP-3D AFM system operating under ambient conditions. NT-MDT NSG30 and Olympus AC160TS probes were used, with typical force constants of 20–80 N/m and tip curvature radii of 5–10 nm. AFM topography images of the samples were processed using the open source software Gwyddion (version 2.38). For each image, first a step line correction in the scanning direction was applied, followed by a three point plane leveling with the mean plane height set to zero value. In the cases of hBN/SiO₂ step edges or hBN terraces, the three points were chosen on the lowest level, e.g., SiO₂. The software was used to calculate the volume of 6P deposited per unit area and to select 6P needle-like crystallites for statistical analysis of their lengths and orientation. AFM was also employed to determine the height of the hBN flakes prior to 6P deposition. For all flakes used in the study, the height was determined considering histograms of an area containing both the flake and the bare SiO₂ substrate. From these, the height was estimated as a peak-to-peak distance and the deviation of the measured height was estimated as a half width at half maximum of the histogram peak that corresponds to the hBN flake.

The morphology of the samples was investigated employing an Asylum Research MFP-3D AFM system operating under ambient conditions. Olympus AC160TS probes were used with typical force constants of 20–80 N/m and tip curvature radii of 5–7 nm. AFM topography images of the samples were processed using the open source software Gwyddion (version 2.38). The thickness of the molecular crystals was estimated considering the total volume on the device active area and presented as an equivalent in complete monolayers (ML) of the bulk structure (in the case of 6P considering up-right standing molecules that form island-like crystallites) of the molecular crystals, since an ideal layer-by-layer growth was not observed. In the considered ranges of the growth temperatures, only the monoclinic β-phase of 6P crystallites is expected (the Baker structure) and the fcc structure of C₆₀. The morphology of C₆₀ films indicated layered growth (step edge height of ~0.8 nm), while 6P films were found to consist of both, islands of up-right standing molecules (~2.6 nm) and needles with flat-laying molecules (taller than 10 nm).