Enhanced ferroelectric properties in La-doped BiFeO3 films by the sol-gel method

High-quality spin-coated Bi1-xLaxFeO3 (x = 0, 0.01, 0.02, 0.03, 0.04, and 0.05) films were successfully produced on fluorine-doped tin oxide (FTO)/glass substrates using a sol-gel approach. The effects of La-doping on the structure, surface morphology, and ferroelectric properties of BFO films were thoroughly investigated. Doping causes structural alterations, which are detected using XRD and Raman spectrum analyses. SEM pictures demonstrate that Bi1-xLaxFeO3 thin films with x = 0.02 have homogeneous fine grains and a greater density, which facilitate the development of ferroelectric characteristics. The XPS study revealed that the incorporation of La3+ significantly reduced the content of Fe2+ and oxygen vacancies, resulting in a massive residual scheme value (2P(r) = 280.4 mu C/cm(2)) and an extremely low leakage current density (J = 1.1 x 10(-6) A/cm(2)). Similarly, the dielectric constant and dielectric loss were significantly improved. Furthermore, UV-vis spectroscopy was used to detect the band gap of the BFO samples, which revealed that the La-doped sample had a smaller band gap than pure BFO. The fundamental principles based on oxygen radical concentration have been described, providing a unique platform to develop improved ferroelectric materials with broad applications.

Automated summary

High-quality spin-coated Bi1-xLaxFeO3 films were produced using a sol-gel approach. The doping of La in the films resulted in structural alterations and improved ferroelectric properties. The incorporation of La3+ reduced Fe2+ and oxygen vacancies, leading to higher residual polarization and lower leakage current density.