High‐Quality Epitaxial Five‐Layer Aurivillius Films with In‐Plane Ferroelectricity for Electrocaloric Cooling
Abstract High‐quality purely c ‐axis oriented epitaxial thin films of the Aurivillius phase Sr 2 Bi 4 Ti 5 O 18 with n = 5 (Sr,Bi)TiO 3 perovskite‐like layers, are grown on SrTiO 3 substrates by pulsed laser deposition. The highest crystalline quality is obtained with a 20 wt.% Bi‐excess target and average stacking order values in the proximity of the ideal value n = 5 are attained for an optimum deposition temperature of 650 °C. Scanning transmission electron microscopy reveals regions with n ranging from 4 to 6 around an average thickness of n = 5, in agreement with the X‐ray diffraction analysis. Interdigital electrodes are used to probe the in‐plane polarization and survey the electrocaloric properties. A maximum adiabatic temperature change of Δ T ∼ 0.95 °C for an electric field of 150 kV cm −1 is observed at ≈135 °C. Larger values are expected at higher temperatures around the ferroelectric Curie temperature, T C . Since T C of Sr 2 Bi 4 Ti 5 O 18 can be tuned by codoping, the findings pave the way toward a large electrocaloric effect at ambient temperature.
Authors
- X. Torrelles (ORCID: https://orcid.org/0000-0002-6891-7793)
- José Manuel Caicedo (ORCID: https://orcid.org/0000-0002-5192-4989)
- G. Subı́as (ORCID: https://orcid.org/0000-0002-9029-1977)
- Eduardo Barriuso (ORCID: https://orcid.org/0000-0003-4732-1218)
- Marco Evangelisti (ORCID: https://orcid.org/0000-0002-8028-9064)
- David Gracia (ORCID: https://orcid.org/0000-0002-3511-3510)
- José Santiso (ORCID: https://orcid.org/0000-0003-4274-2101)
- J. Blasco (ORCID: https://orcid.org/0000-0002-9706-3272)
- Jessica Padilla‐Pantoja (ORCID: https://orcid.org/0000-0002-7769-7753)
- Sara Lafuerza (ORCID: https://orcid.org/0000-0001-8303-932X)
- J. A. Pardo (ORCID: https://orcid.org/0000-0002-0111-8284)
Institutions
- Universidad de Zaragoza (ES)
- Institut Català de Nanociència i Nanotecnologia (ES)
- Instituto de Nanociencia y Materiales de Aragón (ES)
- Institut de Ciència de Materials de Barcelona (ES)
Publication Details
- Journal
- Advanced Electronic Materials
- Published
- 2025-06-06
- DOI
- https://doi.org/10.1002/aelm.202400962
- Primary Topic
- Ferroelectric and Piezoelectric Materials
- Type
- article
- Field-Weighted Citation Impact
- 0.00
Funders
- Ministerio de Ciencia, Innovación y Universidades
- Institut Català de Nanociència i Nanotecnologia
- European Commission
- Generalitat de Catalunya
- Universidad de Zaragoza
- Gobierno de Aragón
- Horizon 2020 Framework Programme
- European Regional Development Fund