**3.1.1 X-ray diffraction (XRD)**

The spectrum of X-ray diffraction (Figure 4) shows that after the deposition, the film is amorphous.

Fig. 4. XRD spectrum of YSZ obtained from different precursor solutions before and after heat treatment at 700 °C for 2 hours.

However, after the heat treatment at 700 °C for 2 hours, the crystallization of zirconia was observed for all the solutions tested. There was no influence of the solvent used in the stabilization of the zirconia phase. The overlapping of the tetragonal and cubic zirconia peaks impedes the determination of the predominant stabilized phase (Wattnasiriwech et al., 2006). Given the importance of determining the stable phase, other techniques can be used to complement the analysis of YSZ X-ray diffraction. In this work Fourier Transform Infrared Spectroscopy (FT-IR) was used to determinate the zirconia phase stabilized.
