Energy storage performance of Nd3+-doped BiFeO3–BaTiO3-based lead-free ceramics

Lead-free ceramics 0.7(Bi1-xNdx)[Fe0.95(Li0.5Nb0.5)0.05]O3-0.3BaTiO3+0.1 wt% MnO2 (x = 0–0.05) solid solutions were synthesized through a solid state sintering route. Phase analysis showed the formation of a single/mixed perovskite structure for all samples. A morphotropic phase boundary between rhombohedral R3c and cubic Pm3‾m appeared in all the samples. The microstructure analysis revealed well-densified ceramics with clear grains and grain boundaries. The dielectric measurement showed broadened and frequency-dependent dielectric maxima, indicating relaxor behavior. With an increase in Nd3+ concentration, the temperature of maximum relative permittivity (Tm) shifted from 564 °C to 330 °C (x = 0.05). The breakdown strength (BDS) was significantly enhanced from 200 kV/cm (x = 0) to 290 kV/cm (x = 0.03). A maximum recoverable energy (Wrec = 3.2 J/cm3) and a high conversion efficiency (η = 73.7%) was achieved for sample x = 0.03, showing promise for use in pulse power systems.