Structural, dielectric and luminescent properties of novel Li1.0Nb0.6Ti0.5O3: Tb3+ ceramics

Novel Li 1.0 Nb 0.6 Ti 0.5 O 3 : Tb 3+ ceramics with favorable luminescent and dielectric properties were prepared by solid-state reaction (SSR) method. The X-ray diffraction (XRD) results indicated that the Tb 3+ ions were effectively dissolved into the “M-phase” matrix synthesized at 1000–1100°C. The ceramic with a dense microstructure could be obtained at 1050°C. The Li 1.0 Nb 0.6 Ti 0.5 O 3 : Tb 3+ ceramics emitted green light at 550 nm and relatively strong red light at 660 nm under the excitation of 440 nm, which were located in the orange-red light region shown in the chromaticity diagram. The color coordinates were (0.5574, 0.4417) for the Li 1.0 Nb 0.6 Ti 0.5 O 3 : 2wt% Tb 3+ ceramic sintered at 1050°C. The quantum efficiency of Li 1.0 Nb 0.6 Ti 0.5 O 3 : 2wt%Tb 3+ ceramic was 19%, which was much higher than that of 9.6% for commercial red Y 2 O 3 : Eu 3+ phosphors. Furthermore, for Li 1.0 Nb 0.6 Ti 0.5 O 3 : 2wt%Tb 3+ ceramic synthesized at 1050°C, the ideal dielectric properties with ε r of 66.263 and Q*f of 5582 GHz were obtained, which might be used as a potentially multifunctional ceramic applied in the fields of LED packaging to improve the lack of red light for blue LEDs combined with yellow phosphors.