8-9th August, 2008 School of Materials Science & Nanotechnology,Jadavpur University
Temperature dependent growth of spherical shaped PbTe nanoparticles
Biplab Paul* and P. Banerji
Materials Science Centre, Indian Institute of Technology, Kharagpur 721302,
India
* Email: biplabpaul2006@yahoo.co.in
Spherical shaped PbTe nanoparticles, in the range 10-30 nm, have been synthesized in a simple aqueous system via chemical preparation route at temperature 500C – 1700C using polyethylene glycol as surfactant to control the size of the particles. The advantage of this route is that, here temperature is only parameter which has controlled the reaction as all the reactions have taken place at atmospheric pressure. Consequently pressure have no role to control the reaction thereby simplifying the process control. For the synthesis of nanocrystals Pb(CH3COO)2.3H2O and Na2TeO3 powders have been used as the lead and tellurium sources respectively, each dissolved in alkaline aqueous solution of NaOH, using sodium borohydride as reducer. Absence of peaks due to Pb and Te or any other phase except PbTe in the XRD diffraction pattern confirms the proper synthesis of the compound has been occurred. With the increase of synthesis temperature, peaks become more intense and narrow because with the increase of synthesis temperature particle size also increases. Average particle size and strain in nanoparticles have been calculated From Williamson-Hall plot. The obtained particle sizes are consistent with the sizes observed from HRTEM and FESEM picture. HRTEM picture confirms large distribution of particle sizes because it follows the log-normal distribution.
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