Structural and optical properties of manganese substituted nanocrystalline bismuth ferrite thin films by sol–gel process

• Nanostructured Mn doped BFO thin films were fabricated by sol–gel process.
• The structural parameters were found to depend upon the Mn doping percent.
• All films possess good transparency.
• The optical properties of the samples were found to depend upon the Mn percent.
• Two strong Photoluminescence emissions observed around 2.53 and 2.33 eV.

Manganese (Mn) substituted nanocrystalline Bismuth Ferrite (BiFe1−xMnxO3) thin films were deposited on quartz substrates by sol–gel process and the effect of the substitution on the structural and optical properties of BiFe1−xMnxO3 system was studied. With the increase in Mn content up to 30%, a distortion in crystal lattice constants and contraction in unit cell volume was observed without any formation of secondary phase. From the AFM photograph ran increase in grain size with the increase in Mn contents was observed. Optical transmittance spectra showed a decrease in transmittance (T%) with the increase in Mn content. Further, it was observed that the presence of Mn lead to the decrease in optical energy band gap of the samples. The effect of Mn substitution on the photoluminescent properties of BiFe1−xMnxO3 system was also studied in order to exploit their possible application in nanoscale optoelectronic devices.