Crystal structure and luminescence properties of the barium europium tetragermanate Ba2Eu2Ge4O13

The tetragermanate Ba 2 Eu 2 Ge 4 O 13 was synthesized for the first time, and its structural and luminescent properties were examined. It crystallizes in a monoclinic system (space group C 2/ c , Z  = 4) and its crystal structure incorporates a unique linear [Ge 4 O 13 ] 10− anion. The photoluminescence spectrum of the sample (λ ex  = 280 nm) contains several intense peaks in the orange-red spectral range corresponding to the 4 f –4 f transitions in Eu 3+ ions.