Limits...
Evaluation of the nanotube intrinsic resistance across the tip-carbon nanotube-metal substrate junction by Atomic Force Microscopy.

Dominiczak M, Otubo L, Alamarguy D, Houzé F, Volz S, Noël S, Bai J - Nanoscale Res Lett (2011)

Bottom Line: For negative tip-substrate bias, a systematic degradation in color and contrast of the electrical cartography occurs, consisting of an important and non-reversible increase of the measured resistance.This effect is attributed to the oxidation of some amorphous carbon areas scattered over the diamond layer covering the tip.For a direct polarization, the CNT and substrate surface can in turn be modified by an oxidation mechanism.

View Article: PubMed Central - HTML - PubMed

Affiliation: Lab, MSSMat, UMR CNRS 8579, Ecole Centrale Paris, Grande Voie des Vignes, Châtenay-Malabry 92290, France. frederic.houze@supelec.fr.

ABSTRACT
Using an atomic force microscope (AFM) at a controlled contact force, we report the electrical signal response of multi-walled carbon nanotubes (MWCNTs) disposed on a golden thin film. In this investigation, we highlight first the theoretical calculation of the contact resistance between two types of conductive tips (metal-coated and doped diamond-coated), individual MWCNTs and golden substrate. We also propose a circuit analysis model to schematize the «tip-CNT-substrate» junction by means of a series-parallel resistance network. We estimate the contact resistance R of each contribution of the junction such as Rtip-CNT, RCNT-substrate and Rtip-substrate by using the Sharvin resistance model. Our final objective is thus to deduce the CNT intrinsic radial resistance taking into account the calculated electrical resistance values with the global resistance measured experimentally. An unwished electrochemical phenomenon at the tip apex has also been evidenced by performing measurements at different bias voltages with diamond tips. For negative tip-substrate bias, a systematic degradation in color and contrast of the electrical cartography occurs, consisting of an important and non-reversible increase of the measured resistance. This effect is attributed to the oxidation of some amorphous carbon areas scattered over the diamond layer covering the tip. For a direct polarization, the CNT and substrate surface can in turn be modified by an oxidation mechanism.

No MeSH data available.


(a) Schematic view of the AFM tip and the «tip-CNT-substrate» junction. A bias voltage V is applied between the tip and the substrate, the arrows represent the direction of the current lines. (b) Series-parallel resistance network corresponding to setup scheme.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
getmorefigures.php?uid=PMC3211423&req=5

Figure 3: (a) Schematic view of the AFM tip and the «tip-CNT-substrate» junction. A bias voltage V is applied between the tip and the substrate, the arrows represent the direction of the current lines. (b) Series-parallel resistance network corresponding to setup scheme.

Mentions: The current conduction of the «tip-CNT-substrate» junction is mainly realized along the CNT radial direction (see Figure 3a). A schematic model of the resistance network for the nanocontact between the tip and the sample can be imagined in the following way with series-parallel resistances (Figure 3b), which is consistent with the previously published results [19,29]. The global resistance measured can thus be considered as the sum of several contributions:(1)


Evaluation of the nanotube intrinsic resistance across the tip-carbon nanotube-metal substrate junction by Atomic Force Microscopy.

Dominiczak M, Otubo L, Alamarguy D, Houzé F, Volz S, Noël S, Bai J - Nanoscale Res Lett (2011)

(a) Schematic view of the AFM tip and the «tip-CNT-substrate» junction. A bias voltage V is applied between the tip and the substrate, the arrows represent the direction of the current lines. (b) Series-parallel resistance network corresponding to setup scheme.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC3211423&req=5

Figure 3: (a) Schematic view of the AFM tip and the «tip-CNT-substrate» junction. A bias voltage V is applied between the tip and the substrate, the arrows represent the direction of the current lines. (b) Series-parallel resistance network corresponding to setup scheme.
Mentions: The current conduction of the «tip-CNT-substrate» junction is mainly realized along the CNT radial direction (see Figure 3a). A schematic model of the resistance network for the nanocontact between the tip and the sample can be imagined in the following way with series-parallel resistances (Figure 3b), which is consistent with the previously published results [19,29]. The global resistance measured can thus be considered as the sum of several contributions:(1)

Bottom Line: For negative tip-substrate bias, a systematic degradation in color and contrast of the electrical cartography occurs, consisting of an important and non-reversible increase of the measured resistance.This effect is attributed to the oxidation of some amorphous carbon areas scattered over the diamond layer covering the tip.For a direct polarization, the CNT and substrate surface can in turn be modified by an oxidation mechanism.

View Article: PubMed Central - HTML - PubMed

Affiliation: Lab, MSSMat, UMR CNRS 8579, Ecole Centrale Paris, Grande Voie des Vignes, Châtenay-Malabry 92290, France. frederic.houze@supelec.fr.

ABSTRACT
Using an atomic force microscope (AFM) at a controlled contact force, we report the electrical signal response of multi-walled carbon nanotubes (MWCNTs) disposed on a golden thin film. In this investigation, we highlight first the theoretical calculation of the contact resistance between two types of conductive tips (metal-coated and doped diamond-coated), individual MWCNTs and golden substrate. We also propose a circuit analysis model to schematize the «tip-CNT-substrate» junction by means of a series-parallel resistance network. We estimate the contact resistance R of each contribution of the junction such as Rtip-CNT, RCNT-substrate and Rtip-substrate by using the Sharvin resistance model. Our final objective is thus to deduce the CNT intrinsic radial resistance taking into account the calculated electrical resistance values with the global resistance measured experimentally. An unwished electrochemical phenomenon at the tip apex has also been evidenced by performing measurements at different bias voltages with diamond tips. For negative tip-substrate bias, a systematic degradation in color and contrast of the electrical cartography occurs, consisting of an important and non-reversible increase of the measured resistance. This effect is attributed to the oxidation of some amorphous carbon areas scattered over the diamond layer covering the tip. For a direct polarization, the CNT and substrate surface can in turn be modified by an oxidation mechanism.

No MeSH data available.