Substitution-driven structural, optical and magnetic transformation of Mn, Co co-doped BiFeO3

Abstract

Transition metal ion doping presents an effective approach to enhance the magnetic properties of BiFeO₃ (BFO). Herein, we explored the impact of dual transition metal ion doping in BFO by preparing BFO and BiFe_0.9Co_xMn_0.1-xO₃ (X = 0, 0.03, 0.05, 0.07, 0.1) samples using a sol-gel method. Comprehensive investigations into the substitution-driven structural, optical and magnetic transformation of Mn, Co co-doped BiFeO₃ have been conducted. The dual ions doping led to the BFO’s structural distortion, which was proved by the Riteveld refinement and Raman spectra. With the addition of dual ions, new energy levels might create additional absorption channels for photons, thereby, increasing photon absorption efficiency and adjusting the bandgap. Analysis of magnetic hysteresis data indicates enhanced magnetism in doped samples. Particularly noteworthy is the coercivity of the BiFe_0.9Co_0.03Mn_0.07O₃ sample, which reaches 14989.6 Oe, compared to the control sample’s coercivity of only 163.9 Oe—almost 100 times greater. This study underscores the efficiency of varying the ratio of double ions in doping samples for enhancing both magnetic and optical properties.