Hutzler A, Fritsch B, Branscheid R, Wu M, Jank M, Spiecker E (2021)
Publication Type: Conference contribution
Publication year: 2021
In this study, charging effects arising due to electron beam irradiation of insulating silicon nitride membranes are used for deliberately manipulating nanostructures during liquid-phase transmission electron microscopy.
Liquid-phase transmission electron microscopy (LP-TEM) has been demonstrated to be a powerful tool for investigating dynamic processes of nanosized structures in liquid environment. The key factor, however, raising this technique to a standard characterization tool is a deep understanding of electron-beam induced effects like temperature increase, charge accumulation and radiolysis of liquid specimen [1,2]. For unraveling those effects, new measurement methods have to be developed including smart data analysis of chemical reactions and motion of nanostructures [3–5].
We show that the electron beam can be utilized for in situ observation and simultaneous manipulation of charged nanoparticles during LP-TEM [6] enabling the displacement and aggregation of complex nanostructures. This is achieved by analyzing two different aqueous solutions containing gold nanoparticles coated with CTAB and citrate, respectively, in a silicon-based liquid cell architecture fitting into conventional TEM specimen holders. The surfactants introduce a positive Zeta potential in one solution and a negative Zeta potential in the other. The particles are utilized as test charges allowing for the probing of emerging potentials inside the liquid cell during electron-beam irradiation.
The probability of the presence of positively charged nanostructures has its maximum between the center and the edge of the electron beam (Fig. 1(c)) whereas negatively charged nanostructures most probably dwell at the center and at the edge of the beam. This observation brings us to the conclusion that an electrostatic potential is generated by positive charge carriers accumulating at the center of the beam and at its rim. Charge buildup at the rim can be explained by beam-induced charge trapping in the insulating silicon nitride membranes of the liquid cell whereas positive charges accumulating at the center are assumed to consist of mainly radiolytic species. Simulations of the corresponding Donut-shaped potential distribution inside the liquid cell show a high conformance to the measured superdiffusive motion of the nanostructures and explain the measured external forces accelerating the diffusive motion of the particles. Figure 1(a) shows an exemplary micrograph of a particle agglomerate confined in the electron beam and the corresponding forces (Fig. 1 (b)).
The study helps to understand charging effects arising during LP-TEM in general and could be utilized for in situ manipulation and assembly of complex nanostructures [7].
APA:
Hutzler, A., Fritsch, B., Branscheid, R., Wu, M., Jank, M., & Spiecker, E. (2021). Direct Manipulation of Nanostructures Utilizing Donut-Shaped Potential Wells during Liquid-Phase Transmission Electron Microscopy. In Proceedings of the Virtual Early Career European Microscopy Congress 2020.
MLA:
Hutzler, Andreas, et al. "Direct Manipulation of Nanostructures Utilizing Donut-Shaped Potential Wells during Liquid-Phase Transmission Electron Microscopy." Proceedings of the Virtual Early Career European Microscopy Congress 2020 2021.
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