jz7b02875_si_004.avi (34.43 MB)
Multistage Transformation and Lattice Fluctuation at AgCl–Ag Interface
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posted on 2017-11-17, 14:51 authored by Jingshan
S. Du, Jungwon Park, QHwan Kim, Wonho Jhe, Vinayak P. Dravid, Deren Yang, David A. WeitzSolid-state
transformation between different materials is often
accompanied by mechanical expansion and compression due to their volume
change and structural evolution at interfaces. However, these two
types of dynamics are usually difficult to monitor in the same time.
In this work, we use in situ transmission electron microscopy to directly
study the reduction transformation at the AgCl–Ag interface.
Three stages of lattice fluctuations were identified and correlated
to the structural evolution. During the steady state, a quasi-layered
growth mode of Ag in both vertical and lateral directions were observed
due to the confinement of AgCl lattices. The development of planar
defects and depletion of AgCl are respectively associated with lattice
compression and relaxation. Topography and structure of decomposing
AgCl was further monitored by in situ scanning transmission electron
microscopy. Silver species are suggested to originate from both the
surface and the interior of AgCl, and be transported to the interface.
Such mass transport may have enabled the steady state and lattice
compression in this volume-shrinking transformation.