High-Pressure Synthesis, Crystal Structure, And Photoluminescence Properties Of Beta-Y2b4o9:Eu3+

A high-pressure/high-temperature experiment at 7.5 GPa and 1673 K led to the formation of the new compound beta-Y2B4O9. In contrast to the already known polymorph alpha-Y2B4O9, which crystallizes in the space group C2/c, the reported structure could be solved via single-crystal X-ray diffraction in the triclinic space group P1 over bar (no. 2) and is isotypic to the already known lanthanide borates beta-Dy2B4O9 and beta-Gd2B4O9. Furthermore, the photoluminescence of an europium doped sample of beta-Y2B4O9:Eu3+ (8%) was investigated.