Transmission electron microscope-induced structural evolution in amorphous Fe, Co, and Ni oxide nanoparticles.

Area of Science:

• Materials Science
• Nanotechnology
• Electron Microscopy

Background:

• High-energy electron beams in transmission electron microscopes (TEM) can induce structural modifications in materials.
• Amorphous metal oxides are susceptible to electron beam damage, affecting their morphology.

Purpose of the Study:

• To investigate and document reproducible TEM-induced morphological changes in amorphous iron, cobalt, and nickel oxide nanoparticles.
• To understand the transformation process of nanoparticles under electron beam irradiation.

Main Methods:

• Synthesis of amorphous metal oxide nanoparticles using established literature procedures.
• Characterization of nanoparticles via X-ray powder diffraction.
• In-situ observation of morphological transformations using time-resolved, low-dose TEM.

Main Results:

• Observed transformation of solid spherical nanoparticles into core/void/shell structures and subsequently into hollow nanoparticles upon electron beam exposure.
• Demonstrated that the transformation rate is dependent on nanoparticle size and composition.
• Confirmed that these TEM-induced changes are not exclusive to iron oxide nanoparticles.

Conclusions:

• TEM imaging can induce significant morphological alterations in amorphous metal oxide nanoparticles.
• Structural analysis of nanoparticles using TEM requires careful consideration of electron beam effects.
• Low-dose imaging techniques are crucial for accurate structural characterization of nanoparticles in TEM.