A new multifunctional Aurivillius oxide Na0.5Er0.5Bi4Ti4O15: Up-conversion luminescent, dielectric, and piezoelectric properties

Abstract A new Aurivillius oxide Na0.5Er0.5Bi4Ti4O15 (NEBT) was synthesized by conventional solid-state reaction and characterized by X-ray diffraction, scanning electron microscope, luminescent, dielectric, and piezoelectric measurements. The as-prepared NEBT ceramics showed a bright upconversion photoluminescence (UC) while simultaneously exhibited a piezoelectric characteristic. Under 980 nm radiation excitation, three emission bands located at green (532 nm, 556 nm) and red (671 nm) wavelength regions were obtained at room temperature. The fluorescence intensity ratio of two green emission bands (centered at 532,556 nm) was studied as a function of temperature in a range of 173–503 K. The maximum sensor sensitivity was found to be about 0.0017 K−1 (380 K). Dielectric property studies showed that NEBT had a phase transition from ferroelectric to paraelectric at around 665 °C. The annealing temperature dependence of piezoelectric d33 showed stably thermal piezoelectric properties of NEBT. As a multifunctional material, NEBT would be useful in sensor, future optical-electro integration devices.