Eu+2 Emission in Ternary Alkaline Earth Aluminum Fluorides

The ternary systems where , were examined for compatibility triangles and compounds. The compounds and were found, each with three polymorphs. The β‐ and γ‐forms in the compound could be quenched. The two low‐temperature (α) forms show strong line emission at 358 to 360 nm with Eu+2 activation, resulting from absorption into the 5d states and emission from the 6P7/2 levels to the 8S7/2 ground state. The β‐ and γ‐forms of contain a band emission and a much weaker line.