Recently, the team of academician Zhang Ze and researcher Wang Jiangwei from the School of Materials Science and Engineering of Zhejiang University skillfully designed in-situ experiments in transmission electron microscopy to study the defect dynamics characteristics of gold nanocrystals under ultrashort electric pulse conditions (~ 3 ns), reveal the non-directional movement mechanism of Σ 3{112} non-common lattice twin boundary, and systematically discuss electrothermal effect, heat dissipation, skin effect, etc. The quantitative analysis results show that the non-directional movement of the non-coherent twin boundary is caused by the direct interaction of electrons and dislocations, rather than the traditional electronic wind force. After the electric pulse is applied, the interaction between electrons and dislocations can cause the atoms at the dislocation core to oscillate irregularly and deviate from the equilibrium position, which leads to defect migration. At the same time, the vibration of the dislocation core atoms causes certain lattice distortion and residual stress, which leads to the slow relaxation of the non-eutectic twin boundary in the electric pulse gap. The relevant research results of

were published in Nature Communications under the title of "Revealing the pulse-induced electroplasticity by decoupling electron wind force. Doctoral student Li Xing is the first author of the paper, Academician Zhang Ze and Researcher Wang Jiangwei are the corresponding authors of the paper, Professor Zheng He of Wuhan University and Professor Wang Jian of University of Nebraska-Lincoln participated in this work.

Original Link: https://www.nature.com/articles/s41467-022-34333-2

Fig. 1 Construction of In-situ Electric Pulse Experimental Device in TEM

Fig.2 Non-eutectic Twin Boundary Migration

Caused by Pulse in Au Nanocrystals fig.3 Non-directional movement of Σ3{112} non-co-lattice twin boundary under the action of electric pulse

Fig..4 In-situ sample rod

produced by Anhui Zeyou Science and Technology Co., Ltd. used in the experiment, in this research results: the researchers used gold nanocrystals as the research object to study the dynamic changes of crystal defects under the action of electric pulses. They used nanosecond (~ 3ns) electrical pulse widths to minimize the Joule heating effect while minimizing the defect density and eliminating potential defect interactions. The generation, movement and annihilation of defects are systematically studied, and the theory of electrical activation is further improved and developed. It provides atomic scale evidence for revealing the microscopic origin of electroplasticity and provides theoretical guidance for the failure of micro/nano electromechanical systems.