Retardation of Liquid Indium Flow in Indium Oxide Nanotubes

Abstract

High-resolution transmission electron microscopy and energy-dispersive X-ray analysis carried out on indium oxide nanotubes grown by a chemical vapor deposition technique show the presence of indium metal segments along the indium oxide (IO) nanotube axis having one end closed. A real-time HRTEM video in continuous mode imaging has been carried out to study the directional flow of liquid indium. Electron-beam-induced heating results in the increase in indium vapor pressure and desorption of gases at the closed end of the IO nanotubes. This buildup of differential pressure between open and closed columns leads to the flow of indium away from the closed end of the IO nanotube. Interestingly, the indium flow rate was observed to decrease from 2.8 to 0.3 nm/s with a corresponding decrease in the nanotubes’ diameter from 138 to 38 nm. This study indicates that the wetting properties of the liquid−host nanotube interface critically decides the fluid dynamics at nanoscale, and depending upon the interfacial properties, enhancement or retardation of flow can be observed on the reduction of the nanotube diameter.

Tunable Growth of Indium Oxide from Nanoflute to Metal-Filled Nanotubes

“…Figure 5a reveals the observed initial diameter of In embedded during the growth of nanocavities embedded IO nanowires and confirmed the proposed growth mechanism, while the presence of indium in IO nanotubes was confirmed using STEM-EDX elsewhere. 38 Nearly 2−4 nm voids at growth temperature may exert an order of magnitude higher pressure than nanocavity of 10−60 nm in In-filled IO nanotubes and results in the In out-diffusion and hence the formation of nanoscale voids (Figure 5a). These voids further coalesce and form the hexagonal nanocavity inside the IO nanowire.…”

“…Some of the nanotubes grown with set II were observed partially filled with In, Figure 5b, indicating the possibility of In out-diffusion from the thin IO shell during the growth. 38 Finally, the representative gas sensing response of nanocavity decorated IO nanowires is shown in Figure 6a. The inset shows the electrodes used to measure the gas sensing.…”

Dynamic nanocrystal response and high temperature growth of carbon nanotube–ferroelectric hybrid nanostructure

“…12 Kumar et al report the movement of liquid indium metal inside the indium oxide nanotubes in the presence of an energetic e-beam; however, the main reason for such action was the generated heat from e-beam solid interaction. 13 They also observed real time rocket type propulsion in the metal lled indium oxide. 14 Knechtel et al showed the reversible bending of carbon nanotubes with change in the current density of irradiated e-beam of transmission electron microscope.…”

“…7 The dynamic behavior of gases, liquids and solids was studied in the context of its movement across the channel of MWCNT. [12][13][14][15][16] The movement of water droplets across the inner cavity of the CNTs due to the capillary forces has been observed, but it is feasible only if the surface tension of the lling liquid is below the cut-off value of 100-200 mN m À1 . 12 Kumar et al report the movement of liquid indium metal inside the indium oxide nanotubes in the presence of an energetic e-beam; however, the main reason for such action was the generated heat from e-beam solid interaction.…”

Highly sensitive humidity sensor based on amorphous Al2O3nanotubes

“…In addition, it is more interesting that not only can the tube-like nanostructures provide an effective channel for vapor transport, but the flow rate of liquid can be largely enhanced in the nanotunnels. 13 Thus, it can be expected that the response/ recovery speed of the sensor, based on porous nanostructures, is much faster to humidity. Therefore, it's worth using porous nanostructures instead of compact layers.…”