Modeling of the evolution of dielectric loss with processing temperature in ferroelectric and dielectric thin oxide films

TL;DR

This paper presents a theoretical model explaining the observed non-monotonic evolution of dielectric loss with processing temperature in ferroelectric and dielectric thin oxide films, supported by experimental data on (Ba,Sr)TiO3 films.

Contribution

It introduces a new theoretical framework linking crystallization stages to dielectric loss changes in thin films.

Findings

Dielectric loss initially increases then decreases with temperature.

Experimental data aligns with the proposed model.

Crystallization processes influence dielectric properties.

Abstract

It was experimentally found that the evolution of dielectric loss with processing temperature displays a common trend in ferroelectric and dielectric thin oxide films: firstly an increase and then a decrease in dielectric loss when the processing temperature is gradually raised. Such a dielectric response of ferroelectric/dielectric thin films has been theoretically addressed in this work. We propose that at the initial stage of the crystallization process in thin films, the transformation from amorphous to crystalline phase should increase substantially the dielectric loss; then, with further increase in the processing temperature, the coalescent growth of small crystalline grains into big ones could be helpful in reducing the dielectric loss by lowering grain boundary densities. The obtained experimental data for (Ba,Sr)TiO3 thin films with 500 nm in thickness were analyzed in terms of the model developed and shown to be in a reasonable agreement with the theoretical results.