The dependence of paramagnetic and optical characteristics of Mn:CdS nanoparticles on high-temperature synthesis conditions

Paramagnetic Mn:CdS nanoparticles were synthesized by a colloidal method in a nonpolar solvent. The temperature and duration of synthesis were varied. The sizes of synthesized nanoparticles were determined by x-ray diffraction and dynamic light scattering in a crystal state and in an organic solvent. How optical (electronic absorption and luminescence spectra) and magnetic properties of synthesized compounds change with the reaction conditions were studied. A longer synthesis intensifies the migration of manganese ions from the bulk phase of nanoparticles to their surface. This effect is confirmed by changes in electron paramagnetic resonance spectra which characterize the ratio between different types of manganese ions and the shift of luminescence peaks to a shorter wave range.