Limits...
Atom Diffusion and Evaporation of Free-Ended Amorphous SiO x Nanowires: Nanocurvature Effect and Beam-Induced Athermal Activation Effect

View Article: PubMed Central - PubMed

ABSTRACT

Arresting effects of nanocurvature and electron beam-induced athermal activation on the structure changes at nanoscale of free-ended amorphous SiOx nanowire were demonstrated. It was observed that under in situ uniform electron beam irradiation in transmission electron microscope, the near surface atoms at the most curved free end of the nanowire preferentially vaporized or diffused to the less curved wire sidewall. The processing resulted in an intriguing axial shrinkage and an abnormal radial expansion of the wire. It was also observed that with the beam energy deposition rate being lowered, although both the diffusion and the evaporation slowed down, the processing transferred from an evaporation-dominated status to a diffusion-dominated status. These results are crucial not only to the fundamental understanding but also to the technical controlling of the electron beam-induced structure change at nanoscale or nanoprocessing of low dimensional nanostructures.

Electronic supplementary material: The online version of this article (doi:10.1186/s11671-016-1735-8) contains supplementary material, which is available to authorized users.

No MeSH data available.


Related in: MedlinePlus

Evolution of evaporated or diffused volume with irradiation time under different current densities. The inset with the same axis units shows the whole evolution curves of evaporated and diffused volumes under current density of 1 A/cm2
© Copyright Policy - OpenAccess
Related In: Results  -  Collection

License
getmorefigures.php?uid=PMC5120135&req=5

Fig3: Evolution of evaporated or diffused volume with irradiation time under different current densities. The inset with the same axis units shows the whole evolution curves of evaporated and diffused volumes under current density of 1 A/cm2

Mentions: To reveal the beam-induced athermal activation effect on the atom diffusion and evaporation, we studied the real-time diffused and evaporated volumes of nanowires under different current densities (the calculation method can be found in Additional file 1: Supporting Information 2). As shown in Fig. 3, the evolution of the evaporated volume and diffused volume under different current densities were plotted with irradiation time. It was found that with the decrease of current density from 10 to 1 A/cm2, the average evolution rates of evaporated volume and diffused volume decrease from 7.9 × 102 to 1.7 × 101 nm3/s and from 9.4 × 101 to 2.0 × 101 nm3/s, respectively (see Additional file 1: Supporting Information 3). For a further confirmation, we repeated the experiments by changing the current density and got the same conclusions. It thus demonstrates that with the current density or energy deposition rate being lowered, both the diffusion and the evaporation slowed down and vice versa.Fig. 3


Atom Diffusion and Evaporation of Free-Ended Amorphous SiO x Nanowires: Nanocurvature Effect and Beam-Induced Athermal Activation Effect
Evolution of evaporated or diffused volume with irradiation time under different current densities. The inset with the same axis units shows the whole evolution curves of evaporated and diffused volumes under current density of 1 A/cm2
© Copyright Policy - OpenAccess
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC5120135&req=5

Fig3: Evolution of evaporated or diffused volume with irradiation time under different current densities. The inset with the same axis units shows the whole evolution curves of evaporated and diffused volumes under current density of 1 A/cm2
Mentions: To reveal the beam-induced athermal activation effect on the atom diffusion and evaporation, we studied the real-time diffused and evaporated volumes of nanowires under different current densities (the calculation method can be found in Additional file 1: Supporting Information 2). As shown in Fig. 3, the evolution of the evaporated volume and diffused volume under different current densities were plotted with irradiation time. It was found that with the decrease of current density from 10 to 1 A/cm2, the average evolution rates of evaporated volume and diffused volume decrease from 7.9 × 102 to 1.7 × 101 nm3/s and from 9.4 × 101 to 2.0 × 101 nm3/s, respectively (see Additional file 1: Supporting Information 3). For a further confirmation, we repeated the experiments by changing the current density and got the same conclusions. It thus demonstrates that with the current density or energy deposition rate being lowered, both the diffusion and the evaporation slowed down and vice versa.Fig. 3

View Article: PubMed Central - PubMed

ABSTRACT

Arresting effects of nanocurvature and electron beam-induced athermal activation on the structure changes at nanoscale of free-ended amorphous SiOx nanowire were demonstrated. It was observed that under in situ uniform electron beam irradiation in transmission electron microscope, the near surface atoms at the most curved free end of the nanowire preferentially vaporized or diffused to the less curved wire sidewall. The processing resulted in an intriguing axial shrinkage and an abnormal radial expansion of the wire. It was also observed that with the beam energy deposition rate being lowered, although both the diffusion and the evaporation slowed down, the processing transferred from an evaporation-dominated status to a diffusion-dominated status. These results are crucial not only to the fundamental understanding but also to the technical controlling of the electron beam-induced structure change at nanoscale or nanoprocessing of low dimensional nanostructures.

Electronic supplementary material: The online version of this article (doi:10.1186/s11671-016-1735-8) contains supplementary material, which is available to authorized users.

No MeSH data available.


Related in: MedlinePlus