Systematic study of the ferroelectric properties of Pb (Zr_0.5 Ti_0.5) O₃ nanowires

The ferroelectric properties of Pb (Zr0.5 Ti0.5) O3 (PZT) nanowires are investigated using Landau-Ginzburg-Devonshire theory, taking account into the nanowire size, polarization gradient, temperature, and axis stress. It is shown that the Curie temperature, coercive electric field, remnant polarization, dielectric permittivity, and piezoelectric coefficient are all size dependent. It is revealed that the ferroelectric properties disappear below a critical diameter, which depends on the temperature, but they can be recovered under an appropriate axis tension. Our results further show that an unusual thermal fluctuation exists in PZT nanowires with small diameter.