Enhanced durability of designated polarization of PbTiO3 nanodot arrays investigated by piezoresponse force microscopy

We used piezoresponse force microscopy (PFM) to investigate local domain relaxation behavior of overhanging PbTiO3 (PTO) nanodot arrays on platinized silicon substrates, which were prepared by using PbO vapor phase reaction sputtering on micellar monolayer films of polystyrene-block-poly(ethylene oxide) (PS-b-PEO) loaded with TiO2 sol-gel precursor. The overhanging PTO nanodot arrays (92% at a temperature of 100 °C for 365 min) showed better ferroelectric retention than the PTO thin films (80% at the same condition). The enhanced polarization states and the absence of depolarization field due to homogeneous electric field inside the overhanging nanodot allowed for the remarkable durability of designated ferroelectric polarization.