Structural and electric properties of epitaxial na0.5bi0.5tio3-based thin films

Magalhaes B, Engelhardt S, Molin C, Gebhardt SE, Nielsch K, Huhne R (2021)

Publication Type: Journal article

Publication year: 2021

Journal

Coatings MDPI

Book Volume: 11

Article Number: 651

Journal Issue: 6

DOI: 10.3390/coatings11060651

Abstract

Substantial efforts are dedicated worldwide to use lead-free materials for environmentally friendly processes in electrocaloric cooling. Whereas investigations on bulk materials showed that Na0.5Bi0.5TiO3 (NBT)-based compounds might be suitable for such applications, our aim is to clarify the feasibility of epitaxial NBT-based thin films for more detailed investigations on the correlation between the composition, microstructure, and functional properties. Therefore, NBT-based thin films were grown by pulsed laser deposition on different single crystalline substrates using a thin epitaxial La0.5Sr0.5CoO3 layer as the bottom electrode for subsequent electric measurements. Structural characterization revealed an undisturbed epitaxial growth of NBT on lattice-matching substrates with a columnar microstructure, but high roughness and increasing grain size with larger film thickness. Dielectric measurements indicate a shift of the phase transition to lower temperatures compared to bulk samples as well as a reduced permittivity and increased losses at higher temperatures. Whereas polarization loops taken at −100◦C revealed a distinct ferroelectric behavior, room temperature data showed a significant resistive contribution in these measurements. Leakage current studies confirmed a non-negligible conductivity between the electrodes, thus preventing an indirect characterization of the electrocaloric properties of these films.

Involved external institutions

Leibniz-Institut für Festkörper- und Werkstoffforschung Dresden e.V. (IFW) / Leibniz Institute for Solid State and Materials Research Dresden DE Germany (DE) Fraunhofer-Institut für Keramische Technologien und Systeme (IKTS) DE Germany (DE)

How to cite

APA:

Magalhaes, B., Engelhardt, S., Molin, C., Gebhardt, S.E., Nielsch, K., & Huhne, R. (2021). Structural and electric properties of epitaxial na0.5bi0.5tio3-based thin films. Coatings, 11(6). https://doi.org/10.3390/coatings11060651

MLA:

Magalhaes, Bruno, et al. "Structural and electric properties of epitaxial na0.5bi0.5tio3-based thin films." Coatings 11.6 (2021).

BibTeX: Download