Undoped and Mn doped ZnO nanoparticles were synthesized by two novel wet chemical techniques: sol-gel and gel-combustion. We were able to prepare Mn- doped ZnO nanoparticles free from second phase at calcing temperature 5400 and 500 degree centigrades using sol-gel and gel combustion, respectively. It is found that the well crystallization is better performed in the ZnO based solid solution prepared by the sol-gel method, comparing to the samples synthesized by the gel-combustion method. Transmission electron microscopy observations on particles size distribution show that the nanoparticles synthesized by the gel-combustion method, are smaller than the nanoparticles prepared by the other technique. The differences in the phase formation and structural properties of nanopowders obtained from both methods were studied by using X-ray diffraction analysis. Optical characterizations such as vibrational properties, lattice dynamical parameters, absorption edges and optical band gap energies were carried out by using the IR and UV-Vis spectroscopy. The quantitative estimations lead to the conclusion that the type of synthesis method mostly affects the average particle size and the optical band gap energy of the prepared samples are very important.

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