Open AccessVibrationally Induced Photophysical Response of Sr 2 NaMg 2 V 3 O 12 :Eu 3+ for Dual‐Mode Temperature Sensing and Safety Signs
Author(s) -
Bindhu Amrithakrishnan,
Naseemabeevi Jawahar I.,
Ganesanpotti Subodh
Publication year - 2022
Publication title -
advanced photonics research
Language(s) - English
Resource type - Journals
ISSN - 2699-9293
DOI - 10.1002/adpr.202100159
Subject(s) - luminescence , excited state , phosphor , analytical chemistry (journal) , raman spectroscopy , quenching (fluorescence) , thermochromism , photoluminescence , population , relaxation (psychology) , materials science , atomic physics , chemistry , fluorescence , optics , optoelectronics , physics , psychology , social psychology , demography , organic chemistry , chromatography , sociology
In the dual‐emitting Eu 3+ ‐activated Sr 2 NaMg 2 V 3 O 12 garnet, vibrationally induced thermometric response and thermochromic luminescence are investigated for the first time. Based on the diverse thermal quenching of VO 4 3− and Eu 3+ along with the advantage of variation in the fluorescence intensity ratio, a potential phosphor for sensitive dual‐mode ratiometric and colorimetric temperature sensors is proposed in which maximum absolute and relative sensitivity of 0.0135 K −1 and 1.61% K −1 are obtained at 420 K with a temperature resolution <0.2 K. Efficient thermochromic luminescence in which colorific shift from white (300 K) to red (500 K) is observed such that the requirement of larger number of phonons weakens the nonradiative relaxation of Eu 3+ , resulting in slow quenching, substantiated by estimating radiative and nonradiative decay rates by the 4f–4f intensity method. In contrast, a strong vibrational coupling of excited electrons of the VO 4 3− complex is identified and verified by means of temperature‐dependent Raman and photoluminescence excitation spectra for the first time. Consequently, an increased thermal population of vibrational levels favors rapid thermal quenching of luminescence of VO 4 3− via crossover mechanism. Hence dual‐centered Sr 2 NaMg 2 V 3 O 12 :Eu is an efficient thermometric and thermochromic luminescent material for optical thermometry and safety sign applications in a high‐temperature environment.