Structural, electrical, and magnetic properties of chemical solution deposited Bi(Fe0.95Cr0.05)O3 thin films on platinized silicon substrates

Abstract

Polycrystalline BiFeO3 and Bi(Fe0.95Cr0.05)O3 thin films were deposited on Pt/TiO2/SiO2/Si substrates by chemical solution deposition. Their structural, electrical, and magnetic properties were measured and compared. The prominent splitting around 2θ∼32° for the 104/110 reflections and the resemblance of Raman spectra with BiFeO3 suggests structural invariance upon Cr substitution (≤5%). The surface morphology of the films showed uniform granular grains; roughness and the grain sizes reduced considerably with Cr substitution. In the case of Bi(Fe0.95Cr0.05)O3 thin films, all Raman active modes disappeared at 700 °C suggesting a structural phase transition with the reduced transition temperature compared to pure BFO. The dielectric constant of pure BiFeO3 film is approximately 50 at 1 MHz and it increased to 66 with 5% Cr substitution. The leakage current reduced in Bi(Fe0.95Cr0.05)O3 thin films and the current conduction was due to Poole–Frenkel mechanism compared to the space charge limited current conduction in BiFeO3. The saturated magnetization was observed in both cases with higher saturation magnetization in the case of Bi(Fe0.95Cr0.05)O3 thin films. Higher net polarization and saturated P-V hysteresis were obtained for Bi(Fe0.95Cr0.05)O3 compared with BiFeO3 films.