THE STANNIDES EUPDSN AND EUPTSN

EuPdSn and EuPtSn were prepared front the elements in tantalum tubes a t 1070 K and investigated by X-ray diffraction on both powder as well as single crystals. They crystallize with the TiNiSi type structure of space group Pnma and with Z = 4 formula units per cell. Both structur es were refined from single-crystal; diffractometer data: a = 751.24(9 ), b = 469.15(6), c = 804.31(9) pm. V = 0.2835(1) nm(3) for EuPdSn, an d a = 753.38(7), b = 467.72(4) c = 793.08(7) pm, V = 0.2795(1) nm(3) f or EuPtSn. The structures consist of three-dimensional [PdSu] and [PtS n] polyanionic networks in which the europium atoms are embedded. The crystal chemistry of these stannides Is briefly discussed.