presentation by Dr. Junjie Li: In-Situ Atomic Scale Observation of Interfacial Dynamics: Nucleation, Growth and Coalescence

Monday 13 August 2018 10:00 - 11:00
Published 2018-08-06 17:23 by Kimberly Dick Thelander

Dr. Junjie Li from International Iberian Nanotechnology Laboratory (INL) will give a presentation titled: "In-Situ Atomic Scale Observation of Interfacial Dynamics: Nucleation, Growth and Coalescence"

Abstract: Crystallization plays a relevant role in a wide range of processes involving both natural phenomena and in chemical, pharmaceutical and materials industries. Of these processes, nucleation, which is an initial transformation of a disordered phase into an ordered one, represents a key step in tuning the desired size and manipulating properties of crystalline solids, yet it is also the most challenging part of the process to observe since it takes place at very short time and length scales. To date, many studies have offered direct evidence to classical nucleation theory and two-step nucleation model in solution, both of which claim that stable cluster, amorphous precursors and denser liquid precursors can serve as metastable intermediates in a nucleation process. Here, we unveil the temperature- and size-dependent multistep nucleation and growth mechanisms in supported nanocrystals within an aberration-corrected TEM (AC-TEM) from both cross-section view and plane-view by designing and using suitable material systems. These findings offer atomic-scale view into dynamic processes at solid/solid and liquid/solid interfaces, which help to advance our general understanding of heterogeneous nucleation, Oswald ripening process, crystal growth, and the atomic origin of thin film deposition that governs properties of materials. ''

All are welcome!