Orthorhombic TmGe~1.9, with a ZrSi2-ErGe1.83 intergrowth structure

We report on powder X-ray investigation of binary thulium germanides. Three new compounds have been characterized, TmGe1.83 with the ErGe1.83-type structure (Cmcm; a= 4.050(1) ?, b=29.460(8) ? and c=3.887(1) ?), Tm2Ge5 with the Er2Ge5-type structure (Pmmn: a=4.000(1) ?; b=3.875(1) ?; c=18.103(7) ?) and TmGe1.9 with a new structural type (Pmma; a=3.879(1) ?, b=4.034(1) ? and c=22.544(7) ?). The structure of TmGe1.9 has been solved by powder X-ray diffraction. This new type may be considered as an intergrowth of ZrSi2 and ErGe1.83 blocks.