As shown in the experimental part, CdSe quantum dots doped with cobalt ions prepared by thermal decomposition of organometallic precursors for both Cd2+ and Co2+ ions. Different cobalt ions concentration has been mixed with the Cd-Stearate in the reaction mixture. The prepared samples using different cobalt ion concentration has been characterized via TEM and XRD in order to determine the influence of doping on the magnetic and optical properties. Structural Properties: XRD Investigation: In order to prove that doping with Co2+ ions takes place, the XRD patterns have been investigated for four samples prepared using different cobalt concentration relative to Cd2+ concentration, which represent 0, 2, 10, and 20%. All samples which compared are having the same size about 4.2 nm, and the same optical band gap about 516 nm. The only difference is the doping ratio. Doping of crystal with impurities doesn’t result in appearance of new XRD peaks, but instead of leads to gradual shifts in the lattice parameters of the host material as the dopant concentration is increased from the dilute limit. The shifts arise from the strain induced when the dopant is incorporated into the periodic crystal lattice. The XRD pattern as shown in Figure (1) indicate that the prepared particles have Wurtizite (Wz) crystal structure for both of undoped CdSe, and Co2+-doped CdSe QDs samples. In case of undoped CdSe QDs; where the Wz structure shows four distinct features: the first at 2θ= 23.9° due to the (100), and the three broad features appearing at 2θ=41.82, 45.71, and 49.98° due to the (110), (103), and (112) reflections, respectively. In case of Co2+-doped CdSe with doping ratio of 2%, the three most distinct features of Wz structure are slightly shif... ... middle of paper ... ...tes" J. Amer. Chem. Soc., 115, (1993) 8706. 70. Qu, L.; Peng, Z.A. and Peng, X.;”Alternative Routes toward High Quality CdSe Nanocrystals”, Nano Letters, 1 (2001) 333. 71. Peng, Z.A. and Peng, X.;” Formation of high-quality CdTe, CdSe, and CdS nanocrystals using CdO as precursor", J. Am. Chem. Soc. 123 (2001) 183 72. Mona B. Mohamed, Dino Tonti, Awas Al-Salman, Abdelkrim Chemseddine and Majed El-Chagui. "Synthesis of High Quality Zinc Blende CdSe Nanocrystals" J. Phys. Chem. 10, (2005) 1533. 73. Bawendi, M.G.; “Chemistry and Physics of Semiconductor Nanoclusters”, Abstracts of Papers of the American Chemical Society, 208 (1994) 4-Inor. 74. Emam, A.N.; Girgis, E.; Mostafa, A.A.; Guirguis, O.W.; Mohamed, M.B.,“ Magnetic Doped Semiconductor Nanocrystals: Novel Synthetic Method & Characterization of CdSe Nanocrystals Doped with Co+2 Ions“, in preparation (submitted 2012
Physical Chemistry Laboratory Manual, Physical Chemistry Laboratory, Department of Chemistry, University of Kentucky, Spring 2006.
The purpose of this experiment was to determine the effects of voltage and molarity changes on the fractal dimension of a Cu crystal formed by the re-dox reaction between Cu and CuSO4. Using the introductory information obtained from research, the fractal geometry of the Cu crystals was determined for each set of parameters. Through the analysis of data, it was determined that the fractal dimension is directly related to the voltage. The data also shows that the molarity is inversely related to the fractal dimension, but through research this was determined to be an error.
Jana, N. R., Gearheart, L., & Murphy, C. J. (2001). Wet chemical synthesis of silver nanorods and nanowires of controllable aspect ratio Electronic supplementary information (ESI) available: UV–VIS spectra of silver nanorods. See http://www. rsc.org/suppdata/cc/b1/b100521i. Chemical Communications, (7), 617-618.
Where R expresses the growth rate of the crystal and t, s, c express the temperature, supersaturation and concentration of impurity respectively, in the solution. Different crystal faces have grown at different rates under varying environmental conditions. Growth of good quality single crystals by slow evaporation and slow cooling techniques have required optimize conditions. These are (i) material purification, (ii) Solvent selection, (iii) solubility, (v) seed preparation, (vi) agitation, (vii) crystal habit and (viii) cooling rate.
Cadmium is a naturally occurring element in the earth’s crust. Pure cadmium is a soft silver-white metal, but this form is not common in the environment. Rather, cadmium is most often encountered in combination with other elements such as oxygen (cadmium oxide), chlorine (cadmium chloride), or sulphur (cadmium sulphide). These compounds are all stable solids that do not evaporate, although cadmium oxide is often found as part of small particles present in air.
In this experiment, [Co(NH3)5ONO]Cl¬2 was synthesized with a yield of 1.4314 g. It was then used to obtain UV-Vis Spectroscopy data with other prepared cobalt complexes including [Co(NH3)5(H2O)]Cl3, [Co(NH3)5(Cl)]Cl2 , Co(NH3)5(NO2)]Cl2 and [Co(NH3)6]Cl3. Each compound was a different color. Color, by definition, represents the wavelengths of UV light that a particle reflects. UV-Vis spectroscopy measures the amount of UV light absorbed. The easy way to determine wavelength of absorption from the color of the solution was the use of a color wheel like in Figure 1. The wavelengths of the color opposite of the solution’s color in the color wheel were the expected wavelengths of absorption. Co(NH3)5ONO]Cl¬2 was an reddish-orange color so its wavelength
Nanoparticles are defined as particulate materials with at least one dimension of less than 100 nanometers (nm), even the particles could be zero dimension in the case of quantum dots (Bar et al., 2009). Metal nanoparticles have been of great interest due to their distinctive features such as catalytic, optical, magnetic and electrical properties (Rassaei et al., 2008).
Liao, K., Ting, J. (2006). Characteristics of aligned carbon nanotubes synthesized usin a high-rate low-temperature process. Diamond and Related Materials, 2006, 1210-1216.
Nanoparticles are at the best side of the quickly progressing area of nanotechnology. The potential for Nanoparticles in cancer malignancy treatments and pharmaceutical shipping are endless with novel new programs consistently being investigated. Multi-purpose Nanoparticles play a very important part in cancer malignancy treatments and pharmaceutical shipping. The papers best parts the newest success and progression in cancer malignancy treatments and pharmaceutical shipping. Cancer has a physical obstacle like common endothelial pores, heterogeneous framework, heterogeneous movement etc. For treatments to be effective, it is very important to get over these restrictions. Nanoparticles have attracted the attention of professionals because of their versatile individuality. The treatments of cancer malignancy using focused or focused pharmaceutical shipping. Various Nanodevices can be used without any side effects. They mainly include Dendrimers, quantum dots (QDs), cantilevers, Nanotubes, Nanopores, Nanoshells and Eco-friendly Hydrogels.
22. Rao, C. emsp14N emsp14R, et al. "Graphene: The New Two‐Dimensional Nanomaterial." Angewandte Chemie International Edition 48.42 (2009): 7752-7777.
Figuerola A. et al. Epitaxial CdSe-Au Nanocrystal Heterostructures by Thermal Annealing. Nano Lett., 2010, 10 (8), pp 3028–3036
[7] Chen, Xiaobo and Samuel S. Mao. “Titanium Dioxide Nanomaterials: Synthesis, Properties, Modifications, and Applications." Chemical Reviews 107.7 (2007): 2891-959. ACS Publications. Web. 10 July 2010.
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Plontke, R. (2003, March 13). Chemnitz UT. TU Chemnitz: - Technische Universität Chemnitz. Retrieved April 1, 2014, from http://www.tu-chemnitz.de/en/
Grundmann, Marius. Physics of Semiconductors: An Introduction Including Devices and Nanophysics. New York: Springer, 2006. Print.