Characterization of Nanomechanical, Ferroelectric, and Piezoelectric Properties by Nanoindentation and Piezoresponse Force Microscopy of PbTiO3 Thin Films
文摘
Lead titanate PbTiO3 films were deposited onto Pt(111)/Ti/SiO2/Si(100) substrates by the aerosol assisted chemical vapor deposition (AA-CVD) process followed by thermal annealing at 550 掳C for 12 h. Piezoresponse force microscopic observations revealed a nano laminar domain structure in the PbTiO3 grains, and we attribute the lamellar domains to 180 and 90掳 ferroelectric domains. The polarization-switching mechanism of the domains in the representative PbTiO3 film under an external electric fields has also been studied, and it was revealed that a large-area polarization switching is usually accompanied by the appearance of a new direction of 90掳 domains in order to reduce the stress in the grains. Finally, nanomechanical properties such as the elastic modulus and hardness were evaluated by nanoindentation using the continuous stiffness measurement technique.