Synthesis and Photoluminescence of Cd-doped alpha-MnS Nanowires.

Cd-doped alpha-MnS nanowires (av diam = 70 nm) were synthesized by the chemical vapor deposition of MnCl(2)/CdS powders. They all consisted of single-crystalline rock-salt MnS structures with the [111] growth direction. The X-ray diffraction pattern analysis indicates that 10% Cd doping would expand the lattice constants by 0.3%. As the content of Cd increases, the band edge emission band (2.9 eV) of photoluminescence becomes broader, and the Mn(2+) emission band (1.6 eV), which emerged at temperatures below approximately 150 K, decreases in intensity. The decay time of the 1.6 eV band decreases from 40 to 30 mus when the Cd doping is increased from 0 to 10%. In contrast to the bulk (T(N) = 150 K), the MnS nanowires were found to be paramagnetic with antiferromagnetic interactions. These distinctive magnetic properties of the nanowires have a strong correlation with their photoluminescence, which could be influenced by the nanosize effect and the Cd doping.