Spectroscopic and thermal behavior of ca₈ MgLa(PO₄)₇:Eu(2+),Mn(2+) phosphor powders and polymer composites.

Inorganic phosphates doped with rare-earth and transition-metal ions are of great interest due to their tunable optical properties and potential in white-light-emitting applications. In this study, Ca₈MgLa(PO₄)₇ phosphors co-doped with Eu and Mn ions were synthesized via the solid-state reaction method and comprehensively characterized by structural and spectroscopic techniques. Phase-pure samples with different activator ratios were analyzed to elucidate the correlation between composition, local coordination environment, and photoluminescence behavior. Detailed temperature-dependent emission studies revealed pronounced spectral evolution associated with thermally activated redistribution of Eu emission among crystallographically distinct sites, as well as with host lattice expansion. The observed changes are discussed in terms of energy transfer and electron-phonon coupling mechanisms responsible for broadband emission and thermal quenching. To evaluate the application potential, the compound was mixed with a relevant polymer to produce a composite, which was then characterized spectrally. Additionally, a simulation of its performance under industrial conditions was carried out. Results showed that after 2000 h of aging tests, the quantum efficiency of CaMgLa(PO):1 %Eu:10 %Mn remained stable, with a 10 % increase in luminescence intensity.