Atomic force microscope manipulation of multiwalled and single walled carbon nanotubes with reflux and ultrasonic treatments

Abstract

We are reporting the atomic force microscope (AFM) nanomanipulation of ultrasonically dispersed and reflux-oxidized multiwalled carbon nanotubes (MWCNT) and single walled carbon nanotubes (SWCNT) by controlling the AFM tip with a NanoManipulator on a silicon substrate. The structure and the morphology of the carbon nanotubes (CNT) were confirmed with AFM interfaced with NanoManipulator and transmission electron microscope. The modifying parameter, which controls the force exerted by AFM tip, was set to be 0.5 nA in each case (0.5 nA = 20 nN). Bending was observed in ultrasonically dispersed MWCNTs, whereas, cutting was observed for reflux-oxidized MWCNTs along with the lateral movements. Similar observations were found for SWCNTs with sharp cuts and lateral displacements. The results show that CNTs deform by combining bending and distortion when subjected to large mechanical forces exerted by the tip of the AFM. The magnitude of the force, required to deform the reflux-oxidized CNTs is less than that for the ultrasonically dispersed CNTs, for both MWCNTs and SWCNTs.

Classification ofABO3perovskite solids: a machine learning study

“…For an ideal perovskite, t ¼ 1. Most perovskites have 0:75<t<1:03 (Li et al, 2004;Kumar et al, 2008). Below this range the ABO 3 solid tends to adopt other structure types, e.g.…”

“…Our stated task is of course one that has been studied for several years (Li et al, 2004;Zhang et al, 2007;Feng et al, 2008;Kumar et al, 2008). These studies performed a classification into perovskite or not in the traditional way by using a structure map.…”

“…A structure map (Mooser & Pearson, 1959) is a two-dimensional plot of the values of two features of the known solids and with lines drawn by a pencil and ruler that separate the data points into the two classes of crystal structures. The tolerance and octahedral factors are the two most widely used perovskite features in these plots (Li et al, 2004;Feng et al, 2008;Kumar et al, 2008). We asked new questions: can we improve the predictions by using more than two features?…”

“…Besides the tolerance and octahedral factor feature pairs, we also considered the A and B ionic radii (relative to the ionic radius of O; Kumar et al, 2008), the bond valence distances of A and B from O (Zhang et al, 2007), and the Mendeleev numbers for the A and B atoms (Sutton, 2003;Pettifor, 1995). The values of all these pairs are readily available from published tables.…”

Controlling conducting channels of single-walled carbon nanotube array with atomic force microscopy

“…Atomic force microscopy (AFM) has been a widely used tool to perform various kinds of CNT manipulation. Both contact mode and non-contact mode could be used to translate, bend, roll, split or cut the nanotubes (Hyon et al 2005;Kim et al 2003;Kumar et al 2012;Postma et al 2000;Ziyong et al 2003), either by applying the tip bias (Hyon et al 2005;Kim et al 2003;Park et al 2002) or by exerting mechanical forces (Hertel et al 1998). Devices based on SWNTs were also fabricated through AFM manipulation such as single-electron transistors (Postma et al 2001), field-effect transistors (Avouris et al 1999), diodes (Jiao et al 2008), and so on.…”