Improved electrical properties and dual-mode photoluminescence in (1?x)(Na0.475K0.475Li0.05)NbO3?x(Er0.5Na0.5)TiO3 lead-free multifunctional ceramics

摘要

(1-x)(Na0.475K0.475Li0.05)NbO3-x(Er0.5Na0.5)TiO3 (0≤x≤0.025) lead-free multifunctional ceramics were prepared by a conventional solid-state reaction method. Their phase, photoluminescence, dielectric, ferroelectric and piezoelectric properties were investigated systematically by the X-ray Diffraction (XRD), scanning electron microscopy (SEM) spectrophotometer and electrical property measurements. The relationship of composition, microstructure and electrical properties and the mechanisms of up-conversion and down conversion emissions were analyzed detailed. The results show that the ceramics exhibit the optimum piezoelectric and ferroelectric properties when their compositions lie at the nearby of the morphotropic phase boundary (MPB). Moreover, these ceramics can emit strong 550 nm green light when they were excited by a nearinfrared (980 nm) light and a 486 nm blue light, respectively. Together with the excellent ferroelectric properties and good dielectric properties, these ceramics should be one of the promising candidates for multifunctional optoelectronic applications.