An investigation of the structures of the compounds in the tin-rich part of the Dy-Sn system: Crystal structure of Dy5Sn11 and Dy5Sn13

The structural properties of the compounds in the tin-rich part of the dysprosium-tin system have been studied by X-ray powder diffraction. The crystal structures of six compounds DySn2+x (0 < x < 1) have been characterized. There are four compounds with known structural types: DySn2 with the ZrSi2 structure, Dy3Sn7 with the Gd3Sn7 structure, Dy2Sn5 with the Er2Ge5 structure, DySn3 with the DyGe3 structure and two compounds characterized by new body-centred orthorhombic types (Immm): Dy5Sn11 (a = 4.411 Å, b = 42.50 Å and c = 4.328 Å) and Dy5Sn13 (a = 4.341 Å, b = 48.05 Å and c = 4.405 Å) which result from various insertions of AuCu3 and αPo slabs into the ZrSi2 structure. The relationships and structural evolution are discussed.