Effects of Gd³⁺ substitution on the structure, photoluminescence, scintillation, and thermometric features of Pr³⁺:Lu₂Zr₂O₇ phosphors

Abstract In this study, it is shown how the photoluminescence, scintillation, and optical thermometric properties are managed via the introduction of Gd 3+ ions into Pr 3+ :Lu 2 Zr 2 O 7 . Raman spectra validate that partial replacement of Lu 3+ with Gd 3+ can promote the phase transition of Lu 2 Zr 2 O 7 host from the defective fluorite structure to the ordered pyrochlore one. Upon 289 nm excitation, all the samples emit the 483 ( 3 P 0 → 3 H 4 ), 581 ( 1 D 2 → 3 H 4 ), 611 ( 3 P 0 → 3 H 6 ), 636 ( 3 P 0 → 3 F 2 ), and 714 nm ( 3 P 0 → 3 F 4 ) emissions from Pr 3+ ions, which are enhanced with the addition of Gd 3+ ions due to the modification of crystal structure. Dissimilarly, the X‐ray excited luminescence spectra consist of a strong emission located at 314 nm from Gd 3+ ions ( 6 P 7/2 → 8 S 7/2 ), together with the typical emissions from Pr 3+ ions, which exhibit different dependences on the Gd 3+ concentration. When the luminescence intensity ratio between the 3 P 0 → 3 H 6 (611 nm) and 1 D 2 → 3 H 4 (581 nm) transitions is selected for temperature sensing, Pr 3+ :(Lu 0.75 Gd 0.25 ) 2 Zr 2 O 7 shows the optimal relative sensing sensitivity of 0.78% K −1 at 303 K, which is higher than that of the Gd 3+ ‐free sample. Therefore, the developed Pr 3+ :(Lu, Gd) 2 Zr 2 O 7 phosphors have the applicative potential for optical thermometry, X‐ray detection, and photodynamic therapy.