Impedance Spectroscopy of Lead-Free Ferroelectric Coatings

Abstract

This paper presents impedance measurements of ferroelectric structures involving lead-free oxide and polymer-oxide composite coatings for sensing and energy harvesting applications. Three different ferroelectric materials grown by conventional microfabrication technologies on solid or flexible substrates are investigated for their basic resonant characteristics. Equivalent electrical circuit models are applied to all cases to explain the electrical behavior of the structures, according to the materials type and thickness. The analytical results show good agreement with the experiments carried out on a basic types of excited thin-film piezoelectric transducers. Additionally, temperature and frequency dependences of the dielectric permittivity and losses are measured for the polymer-oxide composite device in relation with the surface morphology before and after introduction of the polymer to the functional film.

Pyroelectric Properties of BaxSr(1−x)TiO3/PVDF-TrFE Coating on Silicon

“…The deposition temperature in the chamber was 110 °C . In our previous studies, this was found to be sufficient for obtaining the necessary microstructure and expect a ferroelectric response, therefore, further post-deposition annealing was not necessary [ 7 , 14 ]. In these studies, where the optimal deposition conditions were found in terms of enhanced piezoelectric response, it the presence of the tetragonal phase was proven, as detected by X-ray diffraction.…”

“…When the material for the new coating is in liquid phase, it leaks in between the grains during film deposition, and lead to the formation of a high-density monolithic layer, consisting of composition with multiple polymer-oxide interfaces. The new bi-layer system is expected to be similar in nature to that of the single-oxide coating, to avoid suppression of ferroelectric behavior [ 6 , 7 ].…”