Optical properties, and thermal stability of Tb3+/Pr3+-doped Na(Y1.5Na0.5)F6 glass ceramics

Abstract

Tb³⁺/Pr³⁺ co-doped Na(Y_1.5Na_0.5)F₆ (NYNF) glass-ceramics (GCs) were successfully prepared through melt crystallization. The crystal structure, thermal properties, and microstructure of the samples were analyzed using X-ray diffraction (XRD), differential scanning calorimetry (DSC), and transmission electron microscopy (TEM). The optimal crystallization temperature was found to be 650 °C for 2 h, resulting in nanocrystal sizes ranging from 50 to 80 nm. Additionally, the luminescence properties and energy transfer mechanisms of this system were examined. It was confirmed that the emission color of the sample varies between green and red-orange as the concentration of Pr³⁺ doping changes. The fluorescence lifetime decay curve confirms that the energy transfer mechanism between Tb³⁺ and Pr³⁺ ions is a dipole-dipole interaction. Temperature-dependent spectrum revealed that the emission color of the sample remained in the orange region when the temperature ranged from 298 K to 573 K. Furthermore, the emission intensity of the sample at 573 K was maintained at 78 % of the emission intensity at room temperature. The activation energy of the sample was 0.41 eV, demonstrating that Tb³⁺/Pr³⁺ co-doped NYNF GCs exhibit excellent thermal stability. These findings suggest that Tb³⁺/Pr³⁺ co-doped GCs hold significant potential for applications in solid-state color rendering and high-temperature monochromatic displays.