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

Synthesis conditions for preparing [(Ba 0.85 Ca 0.15 ) 0.995 Nd 0.005 ](Ti 0.9 Hf 0.1 )O 3 (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 Nd 3+ from 4 D 3/2  →  4 I 9/2 , 2 D 5/2  →  4 I 9/2 and 4 G 11/2  →  4 I 9/2 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.