LAUSR

Abstractγ Stoichiometric NiS shows two crystallographic phases, the low-temperature r-NiS and a high-temperature h-NiS – the later undergoes a first-order metal-to-semiconductor and paramagnetic-antiferromagnetic transition at the same temperature. Doping of nanostructured materials has gathered the attention of several researchers worldwide due to its effectiveness for adjusting the properties of materials. However, h-NiS doping reports in literature were performed mainly with samples not in nanocrystalline form. This paper describes a novel seed induced polyol synthesis of Pd doped h-NiS nanoparticles using sodium sulfide and thiourea as sulfur sources (for seeding and growing stages, respectively) at low temperatures (190 °C). The seed amounts allowed to produce well-dispersed, pure h-NiS nanoparticles with hexagonal habit – which was not possible without seeds at the same conditions. We suggest an effective diffusion of the Pd atoms through the h-NiS lattice via a substitutional-interstitial mechanism, thanks to the control and separation of the nucleation and growth processes during the syntheses.