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Thermochemical synthesis of Mn doped CdS nanoparticles
|Maziar Marandi 1, Nima Taghavinia 1, Azam Iraji zad 1, Seyed Mohammad Mahdavi 1, Zohreh Sedaghat 2|
1. Sharif University of Technology, Azadi Avenue, Tehran 14588, Iran
We report a new method to synthesize CdS:Mn nanoparticles. CdSO4 and Na2S2O3 were used as the precursors while the latter is sensitive to heating process. Na2S2O3 has been considered as a UV sensitive material that finally results in releasing S species in the solution. Here heating process can cause a similar mechanism for dissociation of Na2S2O3. Therefore by heating the precursors in the Ar Atmosphere and in presence of the thioglycerol as the capping agent, CdS nanoparticles could form. The reaction was investigated at different pH, and different temperature from room temperature to 100ºC. The results showed that by increasing the pH the rate of the growth decreases and finally go to a regime that the number of the particles gets constant and only the existing particles grew in size. Also the pH of the solution had an important role in doping process of the nanoparticles. The results of the experiments performed at 100ºC showed that the incorporation of Mn ions inside the CdS nanoparticles is more considerable at lower pHs than the higher pHs. For doing these experiments MnNO3 with different ratios of [MnNO3]/[CdSO4] in the range of 0.01 to 0.1 were used. All experiments carried out at 100 ċ showed that samples moved toward a saturation point in size after a short time. The samples were refluxed for different times to enhance the incorporation of Mn ions inside the particles. The results of the experiments were carried out for the different Mn concentrations demonstrated that increasing the refluxing time increased the intensity of 590 nm Mn photoluminescence peak compared to the intrinsic luminescence peak of undoped CdS nanoparticles. Transmission electron microscopy was the analysis that exhibited crystalline spherical nanoparticles with the sizes around 3nm. X- ray diffraction patterns also demonstrated the crystalline CdS nanoparticles and confirmed the sizes achieved from the TEM images.
Presentation: Oral at E-MRS Fall Meeting 2006, Symposium C, by Maziar Marandi
See On-line Journal of E-MRS Fall Meeting 2006
Submitted: 2006-05-14 11:55 Revised: 2009-06-07 00:44