Crystallization within Intermediate Amorphous Phases Determines the Polycrystallinity of Nanoparticles from...

Area of Science:

• Materials Science
• Nanotechnology
• Crystallization Science

Background:

• Nanocrystal properties depend on size and shape, driving research in solution synthesis.
• Controlling nanoscale morphology is hindered by limited understanding of crystallization, especially the role of noncrystalline intermediates.
• Characterizing intermediate evolution at nanometer and millisecond scales is challenging.

Purpose of the Study:

• To investigate the role of amorphous intermediates in the nucleation and growth of YVO4:Eu nanocrystals.
• To elucidate how intermediate properties influence final nanocrystal size and crystal quality.

Main Methods:

• Utilized in situ X-ray scattering for nonperturbative analysis.
• Focused on the evolution of amorphous intermediates at the nanometer and millisecond scales.

Main Results:

• Nucleation and growth of YVO4:Eu nanocrystals were spatially confined within amorphous intermediates.
• The reactivity and size of these amorphous intermediates determined the final crystals' monocrystalline or polycrystalline nature.
• Intermediate properties directly influenced the final size of the nanocrystals.

Conclusions:

• Amorphous intermediates play a critical role in determining the characteristics of synthesized nanocrystals.
• Designing amorphous intermediates that form rapidly (<6 ms) is key to controlled bottom-up nanoparticle synthesis.
• This research provides insights into optimizing nanoparticle synthesis through intermediate engineering.