Ferroelectric PbTiO3 nanoparticles and their properties

Resumo

The properties of PbTiO₃ nanoparticles (NPs) are studied in the terms of the nanoparticle shell theory and are compared with those of BaTiO₃ NPs. The effect of a(Pb) polarizability of the temperature of ferroelectric transition of PbTiO₃ is discussed. The higher polarizability of a(Ba) and the considerably lower polarizability of a(Pb) determine the higher transition temperature of T_c = 500°C in the case of PbTiO₃ and the lower T_c = 120°C in the case of BaTiO₃. It is shown that the difference in the polarizability values of Ba and Pb atoms also affects the dimensional properties of NPs, at which the ferroelectric transition from the cubic phase to the tetragonal phase occurs: ≈30 nm for PbTiO₃ NPs and 200 nm for BaTiO₃ NPs.