Due to the lack of understanding of the formation mechanism of the material structure and the limited ability to control nanocrystals, the directional synthesis of materials has always been a long-term challenging subject. The emergence of in situ electron microscopy in liquid environment seems to provide a new way to solve this problem.

The team of Han Yongsheng researchers from the Institute of Process Research of the Chinese Academy of Sciences cleverly used the PicoFemto launched by Zeyou Technology (ZepTools).®A series of in-situ SEM liquid electrochemical sample stage design experiments were carried out to study the crystallization process of silver in real time, and the reversible crystallization process of silver crystallization was observed. In order to reveal this reversible crystallization phenomenon, Han Yongsheng's team calculated the free radicals generated by electron beam irradiation. The results show that the concentration of free radicals in the liquid pool fluctuates with time and space due to the diffusion and reaction of free radicals. The modulation of the electron dose rate on the distribution of free radicals led to the formation of different silver structures, confirming the main role of the local concentration field in the evolution of the material structure. The relevant research results were published in the authoritative international journal Research under the title "In Situ Investigation of Dynamic Silver Crystallization Driven by Chemical Reaction and Diffusion.

Original Link: https://doi.org/10.34133/2020/4370817

Figure 1 Construction of In-situ Experimental Environment. (Research, vol. 2020, 4370817) In the experiment of

, a 15 × 15 mm in-situ liquid chip was used. The chip was divided into upper and lower pieces, and the depth of the chip reservoir was 100 um. The upper chip had a 0:25 × 0:25mm amorphous silicon nitride film observation window. The silver nitrate solution is added drop by drop into the reservoir with a micropipette to seal, and the whole reservoir is carried to the PicoFemto of Zeyou Technology (ZepTools).®A series of in-situ SEM liquid electrochemical sample stages are built into the SEM.

Figure 2 In-situ observation of the reversible crystallization process of silver in a liquid environment. (Research, vol. 2020, 4370817)

Figure 3 PicoFemto used in the experiment®Series In Situ SEM Liquid Electrochemical Sample Stage

Figure 4 PicoFemto®Series In Situ TEM Liquid Electrochemical Sample Rods