Vibrationally Induced Photophysical Response of Sr ₂ NaMg ₂ V ₃ O ₁₂ :Eu ³⁺ for Dual?Mode Temperature Sensing and Safety Signs

In the dual-emitting Eu3+-activated Sr2NaMg2V3O12 garnet, vibrationally induced thermometric response and thermochromic luminescence are investigated for first time. Based on diverse thermal quenching of VO43? Eu3+ along with advantage variation in fluorescence intensity ratio, a potential phosphor sensitive dual-mode ratiometric colorimetric temperature sensors is proposed which maximum absolute relative sensitivity 0.0135 K?1 1.61% obtained at 420 K resolution <0.2 K. Efficient colorific shift from white (300 K) to red (500 observed such that requirement larger number phonons weakens nonradiative relaxation Eu3+, resulting slow quenching, substantiated by estimating radiative decay rates 4f–4f method. contrast, strong vibrational coupling excited electrons complex identified verified means temperature-dependent Raman photoluminescence excitation spectra Consequently, an increased population levels favors rapid via crossover mechanism. Hence dual-centered Sr2NaMg2V3O12:Eu efficient luminescent material optical thermometry safety sign applications high-temperature environment.