Composition controlled microstructural, photoluminescent, dielectric and ferroelectric properties of Dy3+ and isovalent ion doped NBBT binary electro-optic ceramic systems

An effective new series of [Na0.5Bi0.5-xDyx]0.94Ba0.06Ti1-yZryO3 (x = 0.01, 0.03, 0.05 & y = 0.02 in mol%) a polycrystalline lead-free electro-optic ceramic system using the traditional solid-state reaction has been extensively analyzed. The Rietveld refinement reveals a perovskite structure with an R3c and P4mm space group. The doping of Dy3+ ions resulted in a reduction in the bandgap and lower absorption at longer wavelengths, which is due to the formation of oxygen vacancies in the system. The luminescence emission curves show an extensive red emission peak at 648 nm and a blue emission peak at 461 nm. The NBBTZ:0.03Dy system, with a maximum dielectric constant of about (εr = 2852), is suitable for battery storage applications. With an increasing x content, the polarization against the electric field (P-E) loop became significantly narrower. By tuning composition, the dual phase coexistence, bandgap narrowing, diffuse phase transition, and ferroelectric nature are significantly enhanced. As a result, the binary electro-optic ceramics system may be a promising choice for NBT-based energy-storage and optoelectronic device applications. [Display omitted] •The dynamic NBBTZ:xDy composites were effectively developed via a traditional solid-state reaction.•Rietveld refinement reveals a pure perovskite structure with a dual space group and the existence of MPB.•Most intense PL emission peak at NBBTZ:0.03Dy system suitable for optoelectronic device applications.•With an increasing Dy3+ content, the polarization against the electric field (P-E) loop became significantly narrower.•By tuning Dy3+ composition in NBBTZ, the dual phase coexistence, bandgap narrowing and ferroelectric nature are enhanced.