Role of Ce³⁺ doping in the photochromic and storage properties of Ca₃MgSi₂O₈

In this study, the role of Ce³⁺ doping in the photochromic, thermostimulated luminescence (TSL), and optically stimulated luminescence (OSL) properties of Ca₃MgSi₂O₈ is analyzed. Ce³⁺ was incorporated into the Ca₃MgSi₂O₈ lattice using high-temperature solid-state synthesis, and its effects on structure, defect formation, charge trapping, and spectroscopic properties were investigated using X-ray diffraction (XRD), photoluminescence (PL), X-ray absorption spectroscopy, optical absorbance, TSL/OSL, and electron paramagnetic resonance (EPR) measurements. The results indicate that Ce³⁺ primarily substitutes for Ca²⁺ ions at the Ca2 site with distorted eightfold coordination. Ce³⁺ doping enhances photochromic efficiency, reaching up to 88% for UV-induced color change, and influences the formation of defect centers responsible for photochromism and luminescence. TSL and OSL analyses indicate the presence of deep charge traps with an activation energy of 1.79 eV, which can be stimulated using blue light. EPR identifies three distinct F⁺-type centers; two of these centers are located in the vicinity of boron impurities, which originate from the borate additive used in the synthesis. The material exhibits excellent photochromic signal stability and a linear TSL dose response up to 40 Gy, suggesting strong potential for dosimetry and optical information storage.