Magnetic Properties of 4-nm Cd₁_-<i>_y</i>Mn<i>_y</i>S Nanoparticles Differing by Their Compositions, <i>y</i>

Abstract

In this paper, we present, for the first time, the magnetic properties of Cd 1 - y Mn y S nanocrystals of average size (4 nm) at various compositions, y . We demonstrate that the Mn−Mn interactions are markedly enhanced compared to the bulk material. As in the bulk phase, the photoluminescence and the EPR hyperfine structure, both attributed to isolated Mn 2+ ions in a tetrahedral coordination, behave similarly with increasing composition. At the opposite of the bulk phase, isolated Mn 2+ ions are observed for a rather large composition ( y = 0.08) in nanocrystals. We attempt to relate the change of the band gap with composition with the various manganese interactions.