The novel hysteresis loop formed and modulated by the built-in electric field with magnetic elements in NaNbO3-based ceramics

The effect of magnetic element doping on dielectric properties and ferroelectric polarization reversal in (1-x)NaNbO3-xNdFeO3 ceramics was investigated. A novel Polarization-Electric Field (P-E) loop was discovered with its direction of maxi polarization opposing the applied electric field. The phenomenon and negative dielectric constant from 9920 to 7990 maybe arise from a built-in electric field generated by interfacial barrier-limited carrier transport and nanoscale ions segregation on domain walls. The results establish a substitution-level-dependent competition mechanism between domain-wall-localized polarization and bulk conduction. It may be provide a novel method of defect engineering on switching devices tuned by built-in electric field.