Exotic chemical arrangements and magnetic moment evolution of NixPt1-x (0 ≤ x ≤ 1) nanoparticles

We present a systematic study on the chemical ordering pattern and the magnetic properties of NixPt1-x (0 <= x <= 1) nanoparticles having a size of 1.5 nm by means of an approach which combines basin hopping structure sampling technique and spin-polarized density functional theory. We found exotic chemical ordering patterns for different Ni/Pt ratios. In addition, we observed a sharp phase transition from non-magnetic to ferromagnetic behaviour around x = 67%. We show that this is a direct consequence of a unique atomic arrangement on the surface in which Ni atoms club together causing the strong Ni-Ni magnetic interaction. The observed magnetic properties are correlated to the electronic density of states. (C) 2018 Elsevier B.V. All rights reserved.