authors |
Tkach, A; Santos, A; Zlotnik, S; Serrazina, R; Okhay, O; Bdikin, I; Costa, ME; Vilarinho, PM |
nationality |
International |
journal |
COATINGS |
author keywords |
KNN thin films; sol-gel; thermal expansion; stress/strain; ferroelectric hysteresis; dielectric properties |
keywords |
ELECTRICAL-PROPERTIES; THERMAL-EXPANSION; CERAMICS; SRTIO3 |
abstract |
If piezoelectric thin films sensors based on K0.5Na0.5NbO3 (KNN) are to achieve commercialization, it is critical to optimize the film performance using low-cost scalable processing and substrates. Here, sol-gel derived KNN thin films are deposited using a solution with 5% of potassium excess on Pt/TiO2/SiO2/Si and Pt/SrTiO3 substrates, and rapid thermal annealed at 750 degrees C for 5 min. Despite an identical film morphology and thickness of similar to 335 nm, an in-plane stress/strain state is found to be tensile for KNN films on Pt/TiO2/SiO2/Si, and compressive for those on Pt/SrTiO3 substrates, being related to thermal expansion mismatch between the substrate and the film. Correspondingly, KNN films under in-plane compressive stress possess superior dielectric permittivity and polarization in the parallel-plate-capacitor geometry. |
publisher |
MDPI |
issn |
2079-6412 |
year published |
2018 |
volume |
8 |
issue |
12 |
digital object identifier (doi) |
10.3390/coatings8120449 |
web of science category |
Materials Science, Coatings & Films |
subject category |
Materials Science |
unique article identifier |
WOS:000455200300035
|