Effect of Co doping on the structure and magnetic properties of Bi_0.8Ba_0.2FeO₃ nanoparticles

A series of Bi0.8Ba0.2Fe1-xCoxO3 (x = 0.00, 0.05, 0.10, and 0.15) samples were synthesized using the tartaric acid modified sol-gel method. The crystal structure of the prepared samples was analyzed by XRD, and the samples co-doped with Ba and Co were all rhombohedral distorted structures with the R3c space group. With an increase in the doping amount, a reduction in lattice parameters was observed along with crystallite sizes consistently being below 62nm. M & ouml;ssbauer spectral analysis at room temperature reveals a good fit with two sextets and a doublet, all attributed to the Fe(3+ )state. This suggests that the charge balance within the samples is maintained through the generation of oxygen vacancies in the system. The hysteresis loops of all samples revealed the weak ferromagnetic of the Co-doped Bi0.8Ba0.2FeO3 nanoparticles. With the increase in Co doping, the magnetic parameters such as saturation magnetization and coercive field significantly improved.