Poster Structure and properties of chromium-sulphide (n=1-6) clusters
In nanomaterials field the physical properties are strongly dependent on the size and the atomic environment. Many theoreticaland experimental studies showed and quantified the strong dependence of magnetism with the local and chemical environmentof the atoms and the dimensionnality of the system [1,2]. For its tendency to polarize antiferromagnetically, chromium remainsa subject of study of topicality more especially as this clusters present properties far from being understood perfectly. This workconcerns the study of the properties of chromium and chromium-sulphide clusters (n=1-6), in the neutral anion and cationstates. Our calculations are carried out within the framework of the density functional theory implemented in VASP code. Theeffects of electronic exchange and correlation are treated in the generalized gradient approximation, with the functional ofPerdew-Burke-Ernzerhof. We determine the geometrical structures of these small clusters and their magnetic and electronicproperties (ionization potential, binding energy, electronic affinity,…). We will study the variation of the physical properties ofpure chromium clusters according to their sizes as well as the effect of the insertion of a sulphur atom. The dimer-based growthpattern found in all considered low-lying isomers of neutral and anionic Cr clusters still persists in doped CrnS clusters. Wefound also that the elongation of Cr-Cr bonds upon the addition of the electronegative S dopant is not enough important toinduce substantial influence on exchange coupling between the chromium atoms. In this communication, we will study the firstfour isomers. The results obtained are discussed in comparison with those of the experiments available.