Incorporation of lead and titanium into a porous alumina membrane during Pb(Zr _0.52Ti _0.48)O ₃ nanotube synthesis

We report the identification and characteristics of lead aluminate (Pb ₂Al ₂O ₅ or PbAl ₁₂O ₁₉)/aluminum titanate (Al ₂TiO ₅) formed as a result of the interaction between a Pb(Zr _0.52Ti _0.48)O ₃ (PZT) precursor and a porous alumina membrane (PAM) during PZT nanotube synthesis. The surface morphology and composition of PZT nanotubes were examined as a function of the etching time and annealing temperature, and the diffusion of elements over nanometer length scales during PZT nanotube formation was investigated based on analysis using field emission transmission electron microscopy, scanning transmission electron microscopy, and energy dispersive x-ray microscopy. As the annealing temperature increased, the volume of lead aluminate/aluminum titanate increased, suggesting that considerable diffusion of Pb and Ti occurred and, in turn, dramatically affected the nanotube characteristics. The diffusion of Pb and Ti was clearly evident, resulting in the formation of a distinct lead aluminate/aluminum titanate at the PZT nanotube/PAM interface.