Luminescent thermal history sensing potential in Pr

In this study, it was demonstrated that Pr3+-doped YAG powder can record thermal history in the temperature range of the template provided by 1100–1600 °C. Upon heating, the material undergoes irreversible structural phase transformations (YAM → YAP → single-phase YAG) induced by 2 h of thermal annealing, leading to permanent changes in both the emission intensity and the excited-state lifetime of Pr3+ ion. Temperature can be determined using two approaches: by analyzing the intensity ratio of the 3P0 → 3H4 and 1D2 → 3H4 emission bands, which increases linearly over 1300–1600 °C with a sensitivity of 0.001 °C−1, and by measuring the luminescence decay time of the 1D2 → 3H4 transition, which decreases linearly over 1100–1600 °C with a sensitivity of 0.38 μs °C−1. The combination of both methods enables durable and quantitative tracking of the material’s thermal history, confirming the suitability of YAG:Pr3+ powders for high-temperature diagnostics, thermal mapping, and monitoring of industrial processes.