Electric field-driven modulation in structural and luminescent properties of Eu³⁺-doped (1 − x)(Na_0.5Bi_0.5)TiO₃ − xBaTiO₃ relaxor ferroelectrics

We investigated the structural, electrical, and luminescent properties of Eu³⁺-doped (1 − x)(Na_0.5Bi_0.5)TiO₃ − xBaTiO₃ (NBT-BT:Eu) relaxor ferroelectrics for x = 0.00–0.08. The introduction of Eu³⁺ generated good emission properties in the samples without weakening their piezoelectric properties. Rietveld refinement structural analysis revealed that the structural phase of NBT-BT:Eu was a mixture of rhombohedral and monoclinic phases with a significant x-dependence. We observed that NBT-BT:Eu underwent a structural phase transformation upon the application of an electric field. Interestingly, the structural changes caused by poling led to a reduction in the emission of Eu³⁺. The poling-driven emission quenching behavior resulted from the increase in the local structural symmetry around Eu³⁺ in the poled samples. We also identified light-induced modulation in the emission of our samples, probably attributed to the photochromic behavior. The multifunctionality of NBT-BT:Eu paves the way for the development of a new type of optoelectronic material.