Synthesis of calcium oxide by means of Two different chemical processes

The growth of samples of CaO (calcium oxide) under conditions of a high calcination temperature (800°C and 900°C) was studied. The CaO samples were prepared using the Pechini method with two different variations. In the first variation, HNO3 and NH4OH were added in order to control the pH. In the second, the pH was not controlled. By means of X-rays, it was seen that for method 1, the phases CaO, CaCO3, and Ca(OH)2 were present. For method 2, only the CaCO3 and Ca(OH)2 phases appeared. By means of Raman spectroscopy, significant changes in the intensity of the peaks were observed, these being greater for method 2. The peaks between 950 cm-1 and 1200 cm-1 also exhibited shifts at low frequencies for first strategy. With respect to photoluminescence, the intensity was greater for the samples prepared via second option. This photoluminescence is an indication that there are more defects in the structure of the samples using method 2. These results indicate the ability that the method of synthesis (Pechini) has for acquiring samples of high quality.