| Autor: |
Semchenko AV; Faculty of Physics and Information Technology, Francisk Skorina Gomel State University, 246019 Gomel, Belarus., Sidsky VV; Faculty of Physics and Information Technology, Francisk Skorina Gomel State University, 246019 Gomel, Belarus., Bdikin I; TEMA, Department of Mechanical Engineering, University of Aveiro, 3810-193 Aveiro, Portugal., Gaishun VE; Faculty of Physics and Information Technology, Francisk Skorina Gomel State University, 246019 Gomel, Belarus., Kopyl S; Department of Physics, CICECO-Aveiro Institute of Materials, University of Aveiro, 3810-193 Aveiro, Portugal., Kovalenko DL; Faculty of Physics and Information Technology, Francisk Skorina Gomel State University, 246019 Gomel, Belarus., Pakhomov O; Laboratory for 'Electro-and Magnetocaloric Materials and Structures', ITMO University, 197101 St. Petersburg, Russia., Khakhomov SA; Faculty of Physics and Information Technology, Francisk Skorina Gomel State University, 246019 Gomel, Belarus., Kholkin AL; Department of Physics, CICECO-Aveiro Institute of Materials, University of Aveiro, 3810-193 Aveiro, Portugal. |
| Abstrakt: |
Pure BiFeO 3 (BFO) and doped Bi 0.9 La 0.1 FeO 3 (BLFO) thin films were prepared on Pt/TiO 2 /SiO 2 /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. |
