Structure and optical properties of KGd(CO3)F2:Eu3+

The crystal structure of KGd(CO3)F2 is solved from single crystal X-ray diffraction, and the luminescence properties of KGd(CO3)F2 are analysed. KGd(CO)3F2:Eu3+ is orthorhombic, of space group Fddd (No. 70), with a=7.006(2) Å, b=11.181(3) Å and c=21.865(6) Å. The three-dimensional network is built up from infinite sheets of GdO4F4 polyhedra in the (a, b) plane, which are linked by the carbonate groups and K+ ions along c. A single crystallographic site for Eu3+ with C2 symmetry, as predicted by X-ray study, is confirmed from the luminescence spectrum recorded at 77 K. Simulation of the crystal field effects is also carried out.