Effect of In and Mn co-doping on structural, magnetic and dielectric properties of BiFeO3 nanoparticles

Bi1-xInxFe1-yMnyO3 (x = 0, y = 0; x = 0.1 y = 0; x = 0, y = 0.1; x = 0.05, y = 0.05) nanoparticles were prepared by a simple cost effective ethylene glycol based solution combustion route. The XRD analysis reveals the single phase rhombohedral structure for BiFeO3 (BFO) and In and Mn co-doped BFO (BIFMO) samples. Some structural distortion is observed for the In and Mn co-doped samples. The co-doping of In and Mn at A-B-site of BFO improves the particles' surface morphology and reduces the average grain size to around 15 nm which evidently affects the magnetic and electrical properties of these nanoparticles. The saturation magnetization enhances significantly from 0.20 emu g(-1) for BFO to 3.50 emu g(-1) for the co-doped sample. The enhanced saturation magnetization is attributed to the size effect. The co-doping decreases the coercivity to around 32 Oe due to a decrease in the magneticrystalline anisotropy. The co-doping improves the dielectric constant and dielectric loss and results in the modification of dielectric behaviour with varying temperatures up to 250 degrees C. All doped samples show high resistivity of the order of 10(9) Omega cm which further improves with co-substitution of In and Mn and is attributed to the presence of small grain size and reduction of oxygen ion vacancies.