Analytical properties of switching current transients in ferroelectrics

Abstract

The increasing application of ferroelectrics in technological applications such as nonvolatile ferroelectric random access memories, capacitors, and energy harvesters highlights the importance of investigating how the characteristics of switching current transients change in response to variation of factors that affect it. This work presents a completely analytical approach based on the Landau-Devonshire (LD) model of phase transitions to quickly study the changes to the properties of switching current transients and back-switching currents in ferroelectric material. The non-linear nature of polarization decay is analyzed based on an exact solution of the Landau-Khalatnikov equation. Exact expressions of the temporal changes in polarization and back-switching current that incorporate the cubic polarization P 3 are derived. Comparison of differences between the exact non-linear model of polarization decay phenomena from the linearized model of polarization decay are discussed. This work shows that the characteristics of the critical switching time phenomenon in partial switching current experiments can be explained by the analytical LD model. Many features of complete and partial switching current transients produced by bipolar electric pulses are successfully modeled analytically by varying factors such as temperature, electric field amplitude, pulse-width and off-time. This work shows that pulse powered switching current behaviour in ferroelectric material can be modeled analytically instead of relying only on numerical approaches to the Landau-Khalatnikov equation.