We investigated the PZT_A3 powder and from the XRD spectra shown in Fig. 1 it CD 437 is evident that the powder exhibits a perovskite crystal structure. The cell parameters were identical to the cell parameters of the as-synthesized powder, within the experimental uncertainty (Table 2). From the SEM images it was evident that the morphology of the PZT_A3 was similar to the morphology of as-synthesized powder (Fig. 2a). We presume that the leaching of almost 5.5% of all the ions did not affect neither the crystal structure nor the morphology of the PZT.
Fig. 4. FT-IR spectra of (a) PZT and PZT_A3, and (b) PZT_A3.Figure optionsDownload full-size imageDownload as PowerPoint slide
Based on the obtained results we deduced ray-finned in the first step the acetate ions adsorb on the PZT surface and form acetate complexes with the PZT. We suspect that the lead preferentially forms acetate complexes and dissolves into the water in the form of soluble Pb(OAc)+. But, because the Zr and Ti ions were also detected in the water, we propose that acetate ions form complexes with these ions as well. Since the concentration of the Pb ions was much higher than that of the Zr and Ti ions (the molar ratio of the leached ions did not correspond to the molar ratio of the elements in the PZT structure) we propose that the PZT follows the incongruent dissolution, thereby forming a Ti,Zr-rich layer on the surface.