Fig. 1. Preparation flow chart of fluorescent ceramics. (a) Mixing and (b) ball milling and drying of raw materials, (c) filtering and shaping of samples, and (d) vacuum sintering of ceramics.

Fig. 2. XRD patterns of YAG:xCe (x = 0.011, 0.013, 0.015, and 0.017) and Y₃Al₅O₁₂ (PDF#33-0040).

Fig. 3. (a) PLE and PL spectra of YAG:xCe (x = 0.011, 0.013, 0.015, and 0.017); (b) TL curves of YAG:xCe³⁺; (c) TL curves with different heating rates of YAG:0.015Ce³⁺; (d) ln(T_m²/β) versus 1/(k_BT_m) based on Eq. (1), originating from two peaks (T₁ and T₂) at TL curve of YAG:0.015Ce³⁺.

Fig. 4. Schematic of the optical storage mechanism of YAG:Ce.

Fig. 5. (a) Schematic illustration of the information storage and readout in ceramics; (b) photographs of YAG:Ce³⁺ ceramics under (i) natural light; (ii) 254 nm Hg UV light; (iii) and (iv) under 254 nm UV light for 5 min and heated to 300°C showing stars, flower, “S”, “I”, “O” and “M”, with photomask covering the sample.