Undoped and Mg doped ZnO nanofibers with different doping concentrations were successfully synthesized using the electrospinning technique. The nanofiber structures were calcined at 300 degrees C, 400 degrees C, 500 degrees C, and 600 degrees C respectively. It was observed that the nanofibers turned into a nanoparticular structure at the calcining temperature of 400 degrees C. The nanoceramic mats were characterized by the Fourier transform infrared-attenuated total reflectance spectroscopy and by the scanning electron microscopy. The electronic band transitions of as-deposited and calcined films were identified by the evaluation of the photoluminescence measurements at room temperature. It was observed that the exitonic transition energy of the ZnO nanostructure blue-shifted to a high energy value with an increasing Mg doping ratio. In order to estimate the decomposition temperature of the nanofibers turning into a nanoparticular structure, the nanofiber structure was calcined at temperatures between 300 degrees C and 400 degrees C, the temperature ramp being 20 degrees C. The evaluation of the emission spectra of the calcined structures show that the decomposition of electrospun nanofibers started at 320 degrees C. In addition, band gap energies of the samples were determined by the transmittance measurement of the samples and by the UV-VIS spectrophotometer at the room temperature. (C) 2012 Elsevier Ltd and Techna Group S.r.l. All rights reserved.