**3.3 Thermal analysis**

In order to determine the characteristics temperature at which solid state processes are taking place, DTA and DSC analysis has been performed. **Figure 5** shows the DTA and DSC curves of the MTO system milled for 35 hrs. The initial weight loss of 6-8% was assigned to the evaporation of humidity during powder's preparation route. Around 400 -450°C, the weight loss was more prominent and apportioned to the formation of secondary phases of MgTiO3 and MgTi2O5. As mechanical activation supports hygroscopy, so weight loss is the highest for the sample with the longest period of milling. So, MTO-35 has more weight loss compared with other different hours milled samples. Also, we have observed some endothermic and exothermic peaks that are related to the weight loss of the sample with temperature.
