Temperature-independent giant dielectric response in transitional BaTiO3 thin films
Everhardt, Arnoud S. (Zernike Institute for Advanced Materials)
Denneulin, Thibaud (Ernst Ruska-Centre for Microscopy and Spectroscopy with Electrons (Jülich, Alemanya))
Grünebohm, Anna (Ruhr-Universität Bochum (Alemanya))
Shao, Yu-Tsun (University of Illinois. Department of Materials Science and Engineering)
Ondrejkovic, Petr (Czech Academy of Sciences)
Zhou, Silang (University of Groningen)
Domingo Marimon, Neus (Institut Català de Nanociència i Nanotecnologia)
Catalan, Gustau (Institut Català de Nanociència i Nanotecnologia)
Hlinka, Jiri (Czech Academy of Sciences)
Zuo, Jian-Min (University of Illinois. Department of Materials Science and Engineering)
Matzen, Sylvia (Université Paris-Saclay)
Noheda, Beatriz (Rijksuniversiteit Groningen. CogniGron Center)

Data:	2020
Resum:	Ferroelectric materials exhibit the largest dielectric permittivities and piezoelectric responses in nature, making them invaluable in applications from supercapacitors or sensors to actuators or electromechanical transducers. The origin of this behavior is their proximity to phase transitions. However, the largest possible responses are most often not utilized due to the impracticality of using temperature as a control parameter and to operate at phase transitions. This has motivated the design of solid solutions with morphotropic phase boundaries between different polar phases that are tuned by composition and that are weakly dependent on temperature. Thus far, the best piezoelectrics have been achieved in materials with intermediate (bridging or adaptive) phases. But so far, complex chemistry or an intricate microstructure has been required to achieve temperature-independent phase-transition boundaries. Here, we report such a temperature-independent bridging state in thin films of chemically simple BaTiO. A coexistence among tetragonal, orthorhombic, and their bridging low-symmetry phases are shown to induce continuous vertical polarization rotation, which recreates a smear in-transition state and leads to a giant temperature-independent dielectric response. The current material contains a ferroelectric state that is distinct from those at morphotropic phase boundaries and cannot be considered as ferroelectric crystals. We believe that other materials can be engineered in a similar way to contain a ferroelectric state with gradual change of structure, forming a class of transitional ferroelectrics. Similar mechanisms could be utilized in other materials to design low-power ferroelectrics, piezoelectrics, dielectrics, or shape-memory alloys, as well as efficient electro- and magnetocalorics.
Ajuts:	European Commission 320832
Drets:	Tots els drets reservats.
Llengua:	Anglès
Document:	Article ; recerca ; Versió sotmesa a revisió
Matèria:	Dielectric permittivities ; Electro-mechanical transducers ; Ferroelectric crystal ; Morphotropic phase boundaries ; Phase-transition boundary ; Piezoelectric response ; Temperature independents ; Vertical polarization
Publicat a:	Applied physics reviews, Vol. 7, Issue 1 (March 2020) , art. 11402, ISSN 1931-9401

DOI: 10.1063/1.5122954

Preprint 19 p, 1.1 MB

El registre apareix a les col·leccions:
Documents de recerca > Documents dels grups de recerca de la UAB > Centres i grups de recerca (producció científica) > Ciències > Institut Català de Nanociència i Nanotecnologia (ICN2)
Articles > Articles de recerca
Articles > Articles publicats