Molecular dynamics study on structural and atomic evolution between Au and Ni nanoparticles through coalescence.

Area of Science:

• Materials Science
• Nanotechnology
• Computational Chemistry

Background:

• Janus Nickel-Gold nanoparticles (NiAu NPs) exhibit complex structure evolution.
• Understanding thermodynamic behavior is crucial for designing nanomaterials.

Purpose of the Study:

• To investigate the thermodynamic evolution of Ni and Au NPs with varying compositions.
• To elucidate the relationship between temperature, particle size, and structural changes.
• To explore atomic segregation and coalescence mechanisms in NiAu NPs.

Main Methods:

• Molecular Dynamics (MD) simulations were employed.
• Simulations focused on Ni and Au nanoparticles with different size ratios.
• Analysis of energy variations and atomic segregation modes at elevated temperatures.

Main Results:

• Energy variation is linked to gold particle size and diverse atomic segregation modes.
• For small gold particles, structural transitions from ordered to disordered and back to ordered states were observed.
• Larger gold particles showed irregular energy variations with potential energy reductions.
• Gold atom segregation to the nickel surface and coalescence processes significantly influence final particle morphology (e.g., dumbbell-like, Janus, core-shell).

Conclusions:

• The study reveals distinct thermodynamic behaviors of NiAu NPs based on gold particle size.
• Atomic segregation and coalescence are key mechanisms driving structural evolution.
• Thermal control offers an effective strategy for designing novel NiAu nanomaterials with tailored properties.