authors |
Tkach, A; Okhay, O; Santos, A; Zlotnik, S; Serrazina, R; Vilarinho, PM; Costa, ME |
editors |
Alexander Pogrebnjak and Valentin Novosad |
chapter title |
Strain effect on the properties of polar dielectric thin films |
nationality |
International |
author keywords |
Thin films, Sol-gel, Thermal expansion, Stress/strain, Ferroelectric hysteresis, Dielectric properties |
abstract |
Low cost scalable processing and substrates are critical for optimized polar dielectric performance of functional oxide thin films if they are to achieve commercialization. Here, we present a comprehensive investigation of the role low-cost MgO, Al 2 O 3 , SrTiO 3 and Si substrates on the structural and electrical properties of sol-gel derived SrTiO 3 (ST) and K 0.5 Na 0.5 NbO 3 (KNN) thin films. The substrate is found to have a strong effect on the stress/stain state and, consequently, on the dielectric and ferroelectric response of the films. A tensile stress induced in-plane by the thermal expansion mismatch between the substrates and the films observed for ST and KNN films deposited on platinized Al 2 O 3 and Si substrates, respectively, lowers the relative permittivity and remanent polarization values in the parallel plate capacitor geometry. In contrast, a compressive stress/strain observed for ST films deposited on MgO/Pt and KNN films on SrTiO 3 /Pt substrates result in superior polarization and dielectric permittivity, corresponding to enhanced out-of-plane displacement of Ti 4+ ions in ST films and Nb 5+ ions in KNN films. It is thus demonstrated that for polycrystalline polar dielectric thin films the relative permittivity and polarization may be optimized through an induced compressive stress state. |
publisher |
Springer Nature Singapore Pte Ltd |
isbn |
978-981-13-6132-6 |
year published |
2019 |
beginning page |
331 |
ending page |
342 |
book digital object identifier (doi) |
10.1007/978-981-13-6133-3 |
link |
https://link.springer.com/book/10.1007/978-981-13-6133-3
|
ciceco authors
impact metrics
dimensions (citation analysis):
|
|
altmetrics (social interaction):
|
|