Crystal Structure of the Compounds DyGa3-xGex (x = 0.08-0.48 and x = 0.68-0.80)

The crystal structure of the binary compound DyGa3 at 600°C belongs to the structure type Ta (Rh0.33Pd0.67)3 (Pearson symbol hP40, space group P63/mmc: a = 6.1617(3), c = 23.0365(18) Å). Progressive substitution of Ge atoms for Ga atoms in DyGa3 at 600°C led to the formation of two ternary compounds: DyGa2.92-2.52Ge0.08-0.48 (structure type Mg3In, hR48, R3m, a = 6.1707(3)-6.22374(10), c = 27.7297(15)-28.1185(5) Å) and DyGa2.32-2.20Ge0.68-0.80 (PuAl3, hP24, P63/mmc, a = 6.0970(3)-6.1091(6), c = 14.3153(8)-14.3528(14) Å). Both structure types belong to the family of close-packed structures, and the increase of the Ge content in the system DyGa3-xGex is accompanied by a decrease of the hexagonality of the close-packing. Both ternary compounds exhibit metallic type of electrical conductivity.