Structural chemistry and physical properties of the rare earth silicide Dy3Si4

Structural chemistry, magnetic and electrical transport properties of the new binary silicide Dy3Si4 were studied. The title compound is a low-temperature phase, formed peritectoidally below 1600 K between DySi and DySi2−x. Its crystal structure, which belongs to the Ho3Si4 type, was determined at room temperature and 100 K from X-ray single crystal intensity data: orthorhombic symmetry, space group Cmcm, unit cell parameters (293 K) a = 4.2107(2) Å, b = 23.892(2) Å, and c = 3.8144(2) Å. The Dy3Si4 structure shows a partial disorder on the silicon substructure, even at low temperature. Its salient characteristics result from the stacking of CrB-like and AlB2-like slabs alternating along the b-axis. Magnetic measurements reveal that Dy3Si4 orders antiferromagnetically at TN = 16 K with an effective moment μeff = 10.8(2)μB in the paramagnetic regime, in good accord with the theoretical Dy3+ free ion moment. The temperature dependence of the electrical resistivity confirms the metallic behaviour of this compound.