Fe/Ni core/shell nanowires and nanorods: a combined first-principles and atomistic simulation study

Area of Science:

• Materials Science
• Condensed Matter Physics
• Nanotechnology

Background:

• Core-shell nanostructures offer unique properties for technological applications.
• Fundamental physical aspects of Fe-Ni core-shell systems require further exploration.
• Hierarchical multiscale modeling provides a powerful approach to study complex nanomaterials.

Purpose of the Study:

• To develop and apply an extensive hierarchical multiscale modeling methodology for Fe-Ni core-shell nanostructures.
• To compute fundamental interface parameters, such as exchange coupling (J_Fe-Ni) and equilibrium bond distances (d).
• To investigate the structural, electronic, magnetic, and hysteresis properties of these nanostructures across various size scales.

Main Methods:

• First-principles calculations to determine interface parameters (J_Fe-Ni = 35.48 meV, d = 2.5 Å).
• Atomistic simulations utilizing parameters derived from first-principles studies.
• Modeling of Fe-Ni core-shell cylindrical nanostructures with varying external diameters (60-110 nm).

Main Results:

• Successful computation of unprecedented interface parameters for Fe-Ni systems.
• Demonstration of the methodology's applicability for higher-scale simulations.
• Observation of diverse magnetic properties and novel complex magnetic states in the studied nanostructures.

Conclusions:

• The developed multiscale methodology enables accurate prediction of fundamental parameters for core-shell nanostructures.
• Fe-Ni core-shell nanostructures exhibit complex magnetic behaviors dependent on size and structure.
• This work provides valuable insights for the design and application of magnetic nanomaterials.