fig3

Figure 3. (A) PLE and PL spectra of SrAl₁₂O₁₉:2%Cr³⁺; (B) PL decay curve of SrAl₁₂O₁₉:x%Cr³⁺; (C) Normalized ML spectra of SrAl₁₂O₁₉:2%Cr³⁺; (D) Schematic diagram of platelike SrAl₁₂O₁₉:x%Cr³⁺ NIR luminescence under different stimuli; (E) ML spectra of SrAl₁₂O₁₉:2%Cr³⁺ recorded under the applied force from 10 to 50 N; (F) Integrated ML intensity as a function of applied load and corresponding linear fitting; (G) ML Repeatability for SrAl₁₂O₁₉:2%Cr³⁺ under periodic load; (H) Integrated ML intensity of SrAl₁₂O₁₉:x%Cr³⁺ under an applied load of 30 N; (I) Integrated ML intensity of SrAl₁₂O₁₉:2%Cr³⁺ synthesis at different temperature. PL: Photoluminescence; ML: mechanoluminescence; PLE: photoluminescence excitation; NIR: near-infrared.