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Atomic Resolution of the graphite surface by STM (scanning tunnelling microscope)

Product No: P2532000

Principle

Approaching a very sharp metal tip to an electrically conductive sample by applying a electrical field leads to a current between tip and sample without any mechanical contact. This so-called tunneling current is used to investigate the electronic topography on the sub nanometer scale of a fresh prepared graphite (HOPG) surface. By scanning the tip line-by-line across the surface graphite atoms and the hexagonal structure are imaged.

Tasks

Prepare a Pt-Ir tip and the graphite (HOPG) sample and approach the tip to the sample.
Investigate the topography of clean terraces and the step height between neighboring terraces in constant-current mode.
Image the arrangement of graphite atoms on a clean terrace by optimize tunneling and scanning parameters. Interpret the structure by analyzing angles and distances between atoms and atomic rows and by using the 2D and 3D graphite model.
Measure and compare images in the constant-height and constant-current mode.

What you can learn about

Tunneling effect
Hexagonal Structures
Scanning Tunneling Microscopy (STM)
Imaging on the sub nanometer scale
Piezo-electric devices
Local Density Of States (LDOS)
Constant-Height and Constant-Current-Mode

Materiallist (Excerpt)	Product	Amount
Compact-Scanning Tunneling Microscope, complete set incl. tools, sample kit and consumables, in aluminium case	09600-99	1
Crystal lattice kit: graphite	39840-00	1
Graphite model, 2D	09620-00	1