abstract
Pure BiFeO3 (BFO) and doped Bi0.9La0.1FeO3 (BLFO) thin films were prepared on Pt/TiO2/SiO2/Si substrates by a modified sol-gel technique using a separate hydrolysis procedure. The effects of final crystallization temperature and La doping on the phase structure, film morphology, and nanoscale piezoelectric properties were investigated. La doping and higher crystallization temperature lead to an increase in the grain size and preferred (102) texture of the films. Simultaneously, a decrease in the average effective piezoelectric coefficient (about 2 times in La-doped films) and an increase in the area of surface non-polar phase (up to 60%) are observed. Phase separation on the films' surface is attributed to either a second phase or to a non-polar perovskite phase at the surface. As compared with undoped BFO, La-doping leads to an increase in the average grain size and self-polarization that is important for future piezoelectric applications. It is shown that piezoelectric activity is directly related to the films' microstructructure, thus emphasizing the role of annealing conditions and La-doping that is frequently used to decrease the leakage current in BFO-based materials.
subject category
Chemistry, Physical; Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering; Physics, Applied; Physics, Condensed Matter
authors
Semchenko, AV; Sidsky, VV; Bdikin, I; Gaishun, VE; Kopyl, S; Kovalenko, DL; Pakhomov, O; Khakhomov, SA; Kholkin, AL
our authors
Andrei Kholkin
Principal Researcher
Svitlana Kopyl
ResearcherProjects
CICECO - Aveiro Institute of Materials (UIDB/50011/2020)
acknowledgements
This work was developed within the scope of the project CICECO-Aveiro Institute of Materials, refs. UIDB/50011/2020 and UIDP/50011/2020, financed by national funds through the FCT/MCTES. The work was performed within the European Union's Horizon 2020 research and innovation programme under the Marie Sklodowska-Curie grant (agreement No 778070). The project was partly supported by RFBR and BRFBR, project numbers 20-58-0061 and T20R-359, respectively. Part of this work was funded by national funds (OE), through FCT-Fundacao para a Ciencia e a Tecnologia, I.P., in the scope of the framework contract foreseen in the numbers 4, 5, and 6 of the article 23, of the Decree-Law 57/2016, of August 29, changed by Law 57/2017, of 19 July.