STM, SEM and AFM Images of Carbon Based Films

This page presents STM, SEM and AFM images of carbon based films created in our lab.

STM and SEM Images of Carbon Nanotubes, Amorphous Carbon and Other Field Emission Materials Grown in our Laboratory

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STM image of carbon nanotubes obtained in our laboratory. The nanotubes stick out of the carbon soot material in the region indicated by the arrow.

SEM image of randomly oriented carbon nanotubes grown using CVD. Image area is 2.2 ´ 1.5 mm².

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SEM image of CVD grown diamond-like carbon film. Bar denotes 10 mm.

SEM image of CVD grown amorphous carbon film with asperities. Bar denotes 10 mm.

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Close-up SEM image of above image showing the sharp asperities. Bar denotes 1 mm.

SEM image of a diamond-coated molybdenum microtip. Bar denotes 10 mm.

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Atomic Resolution UHV STM Studies of Temperature-Dependent Etching of Diamond (100) by Atomic Hydrogen

UHV STM image of the hydrogen-terminated diamond (100)-2x1:H surface exposed to atomic hydrogen for 5 minutes at 500 ºC, acquired using a tip voltage of 1.5 V. Islands having a 3x1 reconstruction are observed. The image area is 200 ´ 200 Å².

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UHV STM image of the hydrogen-terminated diamond (100)-2x1:H surface exposed to atomic hydrogen for 10 minutes at 500 ºC. An etch pit with a bright structure is observed. The image area is 250 ´ 225 Å².

UHV STM image of the non-hydrogen-terminated diamond (100)-2x1 surface after atomic hydrogen etching for 10 minutes at 200 ºC. The surface has a 2x1 reconstruction and is rough at the atomic scale. The image area is 400 ´ 400 Å².

0913_105 cold etch sharpened.jpg (55039 bytes)

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UHV STM image of the non-hydrogen-terminated diamond (100)-2x1 surface after atomic etching for 10 minutes at 500 ºC. The surface is smoother at the atomic scale with larger 2x1 domains. In addition, this surface contains large single atomic vacancy islands, single-height steps and deep pits. These observations shows that etching at this temperature occurs both parallel and perpendicular to the dimer rows.

UHV STM image of the non-hydrogen-terminated diamond (100)-2x1 surface after atomic hydrogen etching for 10 minutes at 1000 ºC. The surface is smooth with large 2x1 domains. Large pits are not observed and vacancy islands consist mainly of single vacancy rows in the direction of the dimer rows. S_B steps are rough and S_A steps are smooth, showing that etching has a low probability of occurring at S_A steps. In addition, double type A steps are observed in which the middle S_B step has been completely etched. These observations show that etching at 1000 ºC is highly anisotropic, with the etch rate along the dimer rows much greater than that perpendicular to the rows. This anisotropic etching supports recent theoretical models of the growth of smooth diamond (100) films.

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Another UHV STM image of the non-hydrogen terminated diamond (100)-2x1 surface after atomic hydrogen etching for 10 minutes at 1000 ºC. Observed are various double type A steps. The image are is 400 ´ 400 Å².

AFM Images of Carbon Nanotubes

AFM image, and its 3D counterpart, of single-walled carbon nanotube (CNT) ropes and bundles. The CNTs were originally suspended in n-dimethylformamide (n-DMF). After being sonicated for approximately 10 minutes, the solution was dropped onto a piece of highly oriented pyrolitic graphite (HOPG). The sample was then placed under vacuum and heated to 200 ºC, and allowed to cool slowly in order to evaporate the n-DMF.

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The above images shown with slope-shading (a method used to enhance the detail of the sample).

Magnified view of the CNTs. The region corresponds to the 10-15 mm ´ 10-15 mm square of the initial CNT image.

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