Synthesis and Thermoluminescence Properties of Mg2+ Doped Nanostructured Aluminium Oxide

Samples of alpha-Al2O3: Mg were obtained using polymer calcination method, with five different concentrations of magnesium. ICP-AES analysis showed the magnesium concentrations to be: 0.47, 0.88, 1.33, 2.61 and 3.36 mol%. Scanning Electronic Microscopy (SEM) indicated the occurrence of a nanometric layer over the alpha-Al2O3 crystals surface and so did the Transmission Electronic Microscopy (TEM). The composition of this layer was found to be magnesium spinel (MgAl2O4) by Electron-beam diffraction, and according to the present results, it is related to the improvement of thermoluminescence (TL) emission efficiency, for gamma-rays irradiated aliquots in the VIS and the near-UV regions. Theoretical deconvolution of experimental data using the Second Order Kinetics model originated into four TL emission peaks at 190, 280, 340 and 430 degrees C.