Über eine neu entdeckte Dimorphie an BaCoEr2O5

On a New Observed Dimorphism of BaCoEr₂O₅ Single crystals of BaCoEr₂O₅ were prepared by CO₂-LASER technique under N₂-atmosphere and investigated by X-ray single crystal methods. It crystallizes with orthorhombic symmetry, space group D-Pnma (a = 12.2787, b = 5.6826, c = 7.0344 Å; Z = 4). The so far unknown crystal structure of BaCoEr₂O₅ belongs to the BaCuLn₂O₅ type forming the dimorphic substance to the previously described Ni type of BaCoEr₂O₅.