title: Atomic-scale insights into structural and thermodynamic stability of Pd-Ni bimetallic nanoparticles.
abstract: Atomic-scale understanding of structures and thermodynamic stability of core-shell nanoparticles is important for both their synthesis and application. In this study, we systematically investigated the structural stability and thermodynamic evolution of core-shell structured Pd-Ni nanoparticles by molecular dynamics simulations. It has been revealed that dislocations and stacking faults occur in the shell and their amounts are strongly dependent on the core/shell ratio. The presence of these defects lowers the structural and thermal stability of these nanoparticles, resulting in even lower melting points than both Pd and Ni monometallic nanoparticles. Furthermore, different melting behaviors have been disclosed in Pd-core/Ni-shell and Ni-core/Pd-shell nanoparticles. These diverse behaviors cause different relationships between the melting temperature and the amount of stacking faults. Our results display direct evidence for the tunable stability of bimetallic nanoparticles. This study provides a fundamental perspective on core-shell structured nanoparticles and has important implications for further tailoring their structural and thermodynamic stability by core/shell ratio or composition controlling.
authors.affiliation: Institute of Theoretical Physics and Astrophysics, Department of Physics, Xiamen University, Xiamen 361005, China. yhwen@xmu.edu.cn.
authors.forename: Rao
authors.initials: R
authors.lastname: Huang
authors.affiliation: Institute of Theoretical Physics and Astrophysics, Department of Physics, Xiamen University, Xiamen 361005, China. yhwen@xmu.edu.cn.
authors.forename: Yu-Hua
authors.initials: YH
authors.lastname: Wen
authors.affiliation: Institute of Theoretical Physics and Astrophysics, Department of Physics, Xiamen University, Xiamen 361005, China. yhwen@xmu.edu.cn.
authors.forename: Zi-Zhong
authors.initials: ZZ
authors.lastname: Zhu
authors.affiliation: State Key Laboratory of Physical Chemistry of Solid Surfaces, Department of Chemistry, Xiamen University, Xiamen 361005, China.
authors.forename: Shi-Gang
authors.initials: SG
authors.lastname: Sun