Polarization switching dynamics in thin-film BaTiO$_{3}$/PbZr$_{0.2}$Ti$_{0.8}$O$_{3}$ bilayer capacitors

In this work, we compare polarization switching and dielectric properties of single- (PbZr$_{0.2}$Ti$_{0.8}$O$_{3}$ (PZT)) and bi-layer (BaTiO$_{3}$/PbZr$_{0.2}$Ti$_{0.8}$O$_{3}$ (BTO/PZT)) ferroelectric thin-film materials. The ferroelectric films were grown by radio-frequency magnetron sputtering on SrRuO$_{3}$/SrTiO$_{3}$ (001) substrates. Pt top electrodes ranging in diameter from 50 um to 200 um were fabricated on top of ferroelectric films. Electrical measurements of switching dynamics and dielectric response revealed a significant difference in polarization switching between single- and bi-layer capacitors. Average remnant polarization in the bilayer was reduced to 60 uC/cm$^{2}$ from 90 uC/cm$^{2}$ polarization in a single layer capacitor, and the switching speed was reduced significantly. In this presentation, we will discuss effects of interfaces and polarization coupling on polarization dynamics and on the dielectric response in ferroelectric multilayers.