Thermally activated phase transitions in Fe-Ni core-shell nanoparticles

• Published in: Frontiers of physics Vol. 14; no. 6; p. 63604
• Main Authors: Wang, Jin-Bo, Huang, Rao, Wen, Yu-Hua
• Format: Journal Article
• Language: English
• Published: Beijing Higher Education Press 01.12.2019; Springer Nature B.V
• Subjects: Astronomy; Astrophysics and Cosmology; Atomic; Condensed Matter Physics; core-shell; Core-shell particles; Energy; Fault detection; Functional materials; Iron; Melting point; Melting points; metallic; Molecular; molecular dynamics; Nanomaterials; nanoparticle; Nanoparticles; Nanotechnology; Nickel; Optical and Plasma Physics; Particle and Nuclear Physics; phase transition; Phase transitions; Physics; Physics and Astronomy; Research Article; Solid phases; Stacking faults; Temperature; Thermal stability; nanoparticle; phase transition; molecular dynamics; metallic; core-shell
• ISSN: 2095-0462; 2095-0470
• DOI: 10.1007/s11467-019-0932-1

Fe-Ni core-shell nanoparticles are versatile functional materials, and their thermal stabilities are crucial for their performances in operating conditions. In this study, the thermodynamic behaviors of Fe-Ni core-shell nanoparticles are examined under continuous heating. The solid-solid phase transition from body centered cubic ( bcc) to face centered cubic ( fcc) in the Fe core is identified. The transition is accompanied with the generation of stacking faults around the core-shell interface, which notably lowers the melting points of the Fe-Ni core-shell nanoparticles and causes even worse thermal stability compared with Ni ones. Moreover, the temperature of the structural transformation is shown to be tuned by modifying the Ni shell thickness. Finally, the stress distributions of the core and the shell are also explored. The relevant results could be helpful for the design, preparation, and utilization of Fe-based nanomaterials.