[49] Selective ferroelectric domain mapping of PbTiO₃ thin film using self-assembled polyelectrolyte

We report the ferroelectric domain mapping of a PbTiO₃ (PTO) thin film using the combination of atomic force microscopy (AFM) and self-assembled polyelectrolytes. Epitaxial PTO thin films (50-nm-thick) deposited onto a Nb-doped SrTiO₃ substrate via pulsed laser deposition exhibit 180° stripe ferroelectric domain structures with a mean domain width of about 10 nm. The ferroelectric PTO domain with upward (downward) polarization is selectively attached to a negatively (positively) charged poly acrylic acid (poly allylamine hydrochloride) layer as a polyelectrolyte through Coulomb interactions. Thereby, the ferroelectric PTO domains can be selectively detected using AFM.