Effects of Sm and Mn co-doping on structural, optical and magnetic properties of BiFeO3 films prepared by a sol–gel technique

•(Bi1–xSmx)(Fe0.95Mn0.05)O3 films were deposited on quartz substrates by sol-gel.•The Sm and Mn co-doping BiFeO3 thin films result in structural distortion.•The optical band gap of the thin films could be tuned by the Sm content.•The thin films have potential applications in storage and optoelectronic devices.

Multiferroic (Bi1−xSmx)(Fe0.95Mn0.05)O3 (xBSFMO, x=0.00, 0.03, 0.06, and 0.09) films were deposited on the quartz substrates by a sol–gel technique. X-ray diffraction patterns indicate that all the films exhibit a polycrystalline perovskite structure with a high degree of (110) preferred orientation. The Sm and Mn co-doping at A- and B-site of BiFeO3 (BFO) results in structural distortion, improves surface morphology and reduces the average grain size of the films. With increasing x from 0.00 to 0.09, the optical band gap of xBSFMO films increases and can be expressed by (2.60+0.8x) eV, which may be due to Burstein–Moss effect. Compared with Mn-doped BFO film, the saturation magnetization (MS) of the (Sm, Mn) co-doped BFO films are significantly enhanced, which provides potential applications in information storage.