Theoretical investigation of structural, electronic and magnetic properties for PtnNi55−n (n = 0–55) nanoparticles

Abstract

The composition-dependent icosahedral (ICO) structures of PtnNi55−n bimetallic nanoparticles (NPs) are explored to investigate the structural, electronic and magnetic properties using density functional theory. The excess energy of the structure with Pt/Ni≈1:1 (Pt28Ni27 NP) is the lowest among the study system. It is noticed that the structures with the greater number of Pt–Ni bonds are more energetically stable on account of the fact that the interaction of Pt–Ni bond is stronger than that of Ni–Ni and Pt–Pt bonds. In addition, the density of states of d-band for Ni and Pt in PtnNi55−n NPs reveals that the Ni d-band has a more remarkable effect on Pt d-band than that of Pt d-band on Ni d-band. Furthermore, the magnetic moments of PtnNi55−n NPs clarify the superior magnetic property. The magnetic moment of Pt54Ni1 NP is larger than that of Pt55 when one Ni atom occupies center, while when the Ni atom occupies surface sites, the magnetic moment of Pt54Ni1 is much lower than that of Pt55. For Pt1Ni54 NP, the magnetism is enhanced comparing with Ni55 when one Pt atom occupies edge site.