Mild hydrothermal formation and comparative coprecipitation route for EuTiNbO6 fine phosphor

Abstract Aeschynite-type EuTiNbO 6 fine phosphor with sufficient luminescence intensity was directly formed as homogeneous cuboid particles with high crystallinity in the range of 1–2 μm from precursor solution mixtures of EuCl 3 , TiOSO 4 , and NbCl 5 under weakly basic conditions via hydrothermal treatment at 240 °C for 5 h. The as-prepared aeschynite phase stably existed after heating at 1000–1400 °C for 1 h in air. Under excitation at wavelengths of 395 nm, among all samples before and after heating in air, the as-prepared EuTiNbO 6 fine crystals before heating emitted luminescence with the highest intensity in the red spectral region with strong red and weak orange light corresponding to 5 D 0→ 7 F 2 and 5 D 0→ 7 F 1 transitions of Eu 3+ , respectively. The amorphous coprecipitation powder crystallized into euxenite-type phase at 700–1000 °C and transformed into aeschynite-type phase at 1000–1200 °C. High-temperature heating at 1400 °C was essential for the coprecipitation powder to obtain almost a single phase of aeschynite-type EuTiNbO 6 and sufficient emission intensity.