Pressure-Induced Emitting-Color Controllability in Mn ²⁺ -Doped MgAl ₂ O ₄ Phosphors for High-Sensitivity Multiparameter Optical Manometry

In this report, Mn²⁺-doped MgAl₂O₄ phosphors with good manometric properties are designed to circumvent the shortage of state-of-the-art luminescent manometers. Under 428 nm excitation, the studied samples exhibit intense green emission from Mn²⁺, with the optimal doping concentration determined as 3 mol%. The luminous thermal stability of the synthesized phosphors is verified via temperature-dependent emission spectra, whereas the <i>in situ</i> high-pressure X-ray diffraction patterns confirm their outstanding structural stability with the target pressure range. Moreover, an apparent spectral red shift is found in the final products at elevated pressure, resulting in pressure-triggered emitting-color controllability. Specifically, over 0.24-14.65 GPa, the emission band centroid alters from 526.5 to 560.2 nm (<i>i.e</i>., dλ/d<i>p</i> = 2.36 nm GPa^-1), and the full width at half-maximum (FWHM) increases from 29.3 to 42.8 nm (<i>i.e</i>., dFWHM/d<i>p</i> = 1.26 nm GPa^-1). Furthermore, the manometric behaviors of the resultant phosphors are further characterized using the color coordinates as sensing parameters, contributing to a maximum sensitivity of 0.015 GPa^-1. Our findings confirm that the luminescence properties of the Mn²⁺-doped MgAl₂O₄ phosphors can be precisely regulated via high-pressure stimulus, supporting their potential for high-sensitivity multiparameter optical manometry applications.