Nanoscale Activation Energy Mapping and Leveraging for Accelerating Ferroelectric Domain Nucleation and Growth

The dynamics of ferroelectric domain switching are directly mapped in a PbZr0.2Ti0.8O3 thin film using piezoresponse force microscopy. Employing the rastering tip as a poling electrode to locally apply a fixed bias near the coercive field, while simultaneously monitoring the evolving domain pattern during continuous imaging, the effectively independent switching dynamics for numerous domains are directly investigated. While areal poling follows the anticipated S-curve, this is shown to be the collective outcome of linear terminal radial growth for an ensemble of independently nucleating domains. By repeating such spatially resolved measurements in the same region, but with progressively greater fields, nucleation sites and growth patterns are shown to clearly repeat. This reveals apparent defects which comparatively promote switching, and nucleation times and growth rates that accelerate exponentially. After analyzing and mapping the ratio of activation energies for nucleation to growth, a high density of nucleation sites can possibly be activated with higher poling fields-even if only at the start of a poling process-enabling faster and more efficient switching to be engineered as directly demonstrated.

Automated summary

The dynamics of ferroelectric domain switching in a PbZr0.2Ti0.8O3 thin film were studied using piezoresponse force microscopy. The study found that the polarization of the domains followed an S-curve, and the nucleation sites and growth patterns showed repeatability. By analyzing the activation energy ratio, it was discovered that using higher poling fields can activate more nucleation sites, enabling faster and more efficient switching.