Tailoring synthesis conditions for [(Ba0.85Ca0.15)0.995Nd0.005](Ti0.9Hf0.1)O3 nanopowders by hydrothermal method and their luminescence properties

Abstract

Synthesis conditions for preparing [(Ba0.85Ca0.15)0.995Nd0.005](Ti0.9Hf0.1)O3 (Nd-BCTH) nanopowders by hydrothermal method were tailored using orthogonal experiment method with three factors and three levels. X-ray diffraction measurement, field emission scanning electron microscopy, transmission electron microscopy, surface aperture adsorption analyzer, ultraviolet–visible spectra, and fluorescence spectrophotometer were used to characterized the synthesized nanopowders. Well dispersed Nd-BCTH nanopowders with excellent crystallization and luminescence properties are obtained at reaction temperature of 200 °C, 14 mol⋅L−1 alkali concentration, and 24 h reaction time without adding surfactant. The nanopowders present a pure pseudo-cubic perovskite structure with rhombohedral phase approaching the morphotropic phase boundary (MPB) at room temperature, which present nano-sized particles with slight conglomeration. Using 267 nm light exciting, strong photoluminescent emission peaks are excited at 364 nm, 422 nm and 440 nm in the Nd-BCTH nanopowders, which correlate with the transitions of Nd3+ from 4D3/2 → 4I9/2, 2D5/2 → 4I9/2 and 4G11/2 → 4I9/2 via two processes of non-radiative relaxation and fluorescent transition, respectively. The CIE1931 chromaticity calculation of the emission peaks and fluorescent photograph show that the Nd-BCTH nanopowders emit indigo blue fluorescent light.