The upper Manganese doping limit and its effects on physical properties of lead-free Bi_0.5Na_0.5TiO₃ ceramics

The lead-free piezoelectric, Bi_0.5Na_0.5TiO₃, was synthesized with varying amounts of Manganese (Mn) doping (x = 0.00, 0.02, 0.05, 0.10, 0.15) on the B-site to replace Ti⁴⁺ cations. Herein, the doping limit of Mn is explored along with its effects on the structure and properties of these materials. The temperature-dependent dielectric properties of the materials with a higher manganese doping level have also been comprehensively investigated in the temperature range of 10–700 K. All samples show a high dielectric permittivity, ε_r ~ 4979–3626 at T_m ~ 550–600 K, along with a low dielectric loss. The magnetic study shows that doping with Mn leads to a complex magnetic state, where there is possible clustering of Mn ions, with inter- or intra-cluster interactions becoming dominant at approximately 50 K. These samples may be considered as alternative to lead-free materials with magneto-electric coupling.