Structural, magnetic and optical properties of cobalt and manganese codoped CdS nanoparticles

CdS nanoparticles codoped with cobalt and manganese are synthesized by the surfactant assisted simple chemical coprecipitation method. Single cubic structure without any secondary phase formation is revealed by the XRD data. Small particle size around 4-5 am is estimated from the TEM images. [PR hyperfine splitting constant A around 95 G associated with the presence of Mn ions on the surface of the nanocrystals is observed for all the samples. Variation of ferromagnetic order with Mn content studied by a vibration sample magnetometer is ascribed to the antiferromagnetic (AFM) interactions between the magnetic ions as explained by the bound magnetic polaron (BMP) theory. Surface defect related green emission is observed through photoluminescence (PL) studies. Absence of Mn characteristic emission further confirms the local structure of Mn ions evidenced by EPR results. (C) 2013 Elsevier B.V. All rights reserved.