Sm–Ti co-substituted BiFeO3 thin films prepared by sol–gel technique

In this paper, BiFeO3 (BFO), Bi0.95Sm0.05FeO3 (BSF), BiFe0.95Ti0.05O3 (BFT) and Bi0.95Sm0.05Fe0.95Ti0.05O3 (BSFT) thin films were deposited on the Pt (111)/TiO2/SiO2/Si(100) substrates by sol–gel technique. X-ray diffraction and scanning electron microscope measurements explain that increased lattice constant and uniform surface morphology can be obtained by Sm–Ti co-substitution in BFO thin film. Meanwhile, the dielectric constant is improved up to 230 at 100 kHz and the leakage current density decreases to 1.5 × 10−5 A/cm2 at 300 kV/cm. Consequently, the ferroelectricity of BSFT thin film is remarkably enhanced with 2Pr of 17.024 μC/cm2 at 563 kV/cm. The electrical conductivity of BSFT film at 387 kV/cm is calculated to be 2.8 × 10−12 Ω−1 cm−1.