Polaron relaxation in ferroelectric thin films

TL;DR

This paper investigates dielectric relaxation in ferroelectric thin films, revealing a polaron relaxation phenomenon at cryogenic temperatures that is independent of film morphology and can serve as a defect probe.

Contribution

It identifies a universal polaron relaxation in ferroelectric thin films, extending understanding from bulk perovskites and highlighting its potential as a defect diagnostic tool.

Findings

Relaxation observed at cryogenic temperatures (T<100K).

Activation energy below 200meV for all samples.

Relaxation is independent of film size, morphology, and texture.

Abstract

We report a dielectric relaxation in ferroelectric thin films of the ABO3 family. We have compared films of different compositions with several growth modes: sputtering (with and without magnetron) and sol-gel. The relaxation was observed at cryogenic temperature (T<100K) for frequencies from 100Hz up to 10MHz. This relaxation activation energy is always lower than 200meV. It is very similar to the polaron relaxation that we reported in the parent bulk perovskites. Being independent of the materials size, morphology and texture, this relaxation can be a useful probe of defects in actual integrated capacitors with no need for specific shaping