Tuyển tập báo cáo các nghiên cứu khoa học quốc tế ngành hóa học dành cho các bạn yêu hóa học tham khảo đề tài: Evaluation of the nanotube intrinsic resistance across the tip-carbon nanotube-metal substrate junction by Atomic Force Microscopy | Dominiczak et al. Nanoscale Research Letters 2011 6 335 http content 6 1 335 o Nanoscale Research Letters a SpringerOpen Journal NANO EXPRESS Open Access Evaluation of the nanotube intrinsic resistance across the tip-carbon nanotube-metal substrate junction by Atomic Force Microscopy 1 2 2 3 2 Maguy Dominiczak 1 Larissa Otubo David Alamarguy Frédéric Houzé Sebastian Volz Sophie Noel and Jinbo Bai1 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. Introduction Since the official publication of the carbon nanotubes CNTs images during the period
