Abnormal Eu³⁺ → Eu²⁺ Reduction in Ca_9-xMn_xEu(PO₄)₇ Phosphors: Structure and Luminescent Properties.

ABSTRACT: β-Ca₃(PO₄)₂-type phosphors Ca_9-xMn_xEu(PO₄)₇ have been synthesized by high-temperature solid-phase reactions. The crystal structure of Ca₈MnEu(PO₄)₇ was characterized by synchrotron X-ray diffraction. The phase transitions, magnetic and photoluminescence (PL) properties were studied. The abnormal reduction Eu³⁺ → Eu²⁺ in air was observed in Ca_9-xMn_xEu(PO₄)₇ according to PL spectra study and confirmed by X-ray photoelectron spectroscopy (XPS). Eu³⁺ shows partial reduction and coexistence of Eu²⁺/³⁺ states. It reflects in combination of a broad band from the E

SUBMITTER: Sipina EV 

PROVIDER: S-EPMC9962388 | biostudies-literature | 2023 Feb

REPOSITORIES: biostudies-literature