Polarization Switching and Dielectric Properties of PZT Structures

We have taken an extensive investigation of ferroelectric structures based on Pt/PbZr_0.53Ti_0.47O₃/Pt/Ti/SiO₂/Si (PZT) thin films. Such characteristics as D-E hysteresis loops, C-V and V-I curves, polarization pulse switching, and pyroelectric coefficient were examined in the temperature range between 20 … 200°C. The effects of interface layers and of the process of charge transfer on the dielectric behavior of the ferroelectric thin films were studied as well. Appreciable asymmetric capacitance-voltage curves and hysteresis loops behavior have been observed for some specimens. These results provide an explanation for the model, which describes the PZT structure as a series circuit of three depletion layer capacitors. Following this method for the high field voltage, one can obtain the values of associated parameters, such as the depletion layer capacitance, bulk permittivity, and space-charge density.