Mn(IV)-Substituted Metal(II) Hexafluorido Metallates(IV): Synthesis, Crystal Structures, and Luminescence Properties

We synthesized 16 novel red-emitting Mn(IV)-substituted phosphors of the compositions MgGeF₆ : Mn, MgPbF₆ : Mn, CaMF₆ : Mn (M=Ge, Sn, Pb, Zr, Hf), SrSnF₆ : Mn, “SrTiF₆ : Mn”, BaPbF₆ : Mn, ZnMF₆ : Mn (M=Sn, Pb, Zr, Hf), and CdMF₆ : Mn (M=Pb, Hf) using a dry-chemical fluorination process completely avoiding hydrofluoric acid. In comparison with the commonly used red-emitter K₂SiF₆ : Mn (KSF) with its emission maximum at 630.8 nm, all above Ca and Sr compounds and CdHfF₆ : Mn show a blue-shift of their emission maxima, the compound SrSnF₆ : Mn even by 4.2 nm down to 626.6 nm. The compounds were characterized by powder X-ray diffraction, IR and emission spectroscopy. We additionally present the crystal structures of the unsubstituted compounds CaZrF₆, CaHfF₆, CaPbF₆, CdZrF₆, CdHfF₆, and MgHfF₆, which all crystallize isotypic in the NaSbF₆ structure type. The compound “SrTiF₆” was characterized by powder XRD and studied with evolutionary structure prediction methods, but its crystal structure could not yet be solved.