On the Behavior of Ag Nanowires Under High Temperatures: In Situ Characterization by Aberration- Corrected STEM

Mayoral, A., L.F. Allard, D. Ferrer, R. Esparza and M. Jose-Yacaman, 2012

Image courtesy of J. Mater. Chem.

Abstract

Single crystal nanowires have been monitored at a wide range of temperatures from room temperature up to 900 °C using an aberration-corrected JEOL 2200FS scanning transmission electron microscope in both, bright field and high angle annular dark field, modes. The in situ measurements allowed heating and cooling the material instantaneously at the desired value making able to analyze the behaviour of silver nanowires at atomic resolution. The nanowires which firstly melted and subsequently vaporized left after the reaction empty carbon nanotubes. In addition, a Chevron-like defect has been also observed for the first time in silver nanowires and a structural analysis has been carried out by aberration corrected scanning transmission electron microscopy using high angle annular dark field imaging.

Impact Statement

Observed the structural changes of silver nanowires encapsulated in porous, amorphous carbon nanotubes as function of heat. They report a new type of defect never before seen in metal nanowires. They observe capillary action of the nanotubes and because of the high mobility of silver observe filling and emptying of the nanotubes. They took atomic resolution images at high temperatures using a JEOL 2200FS Cs corrected STEM.