Crystallographic, magnetic and electrical characteristics of some R5−xNi12Sn24+x intermetallics

Stannides with general composition R5−xNi12Sn24+x (R = Y, La, Nd, Sm, Gd, and Dy) were prepared by arc melting and the crystal structure peculiarities for this series were studied. Intermetallics with R = Y, La, Nd, Sm, and Gd belong to the cubic GdNi2.67Sn5.44 structure type (space group Im−3), while Dy4Ni12Sn25 compound crystallizes in the Ce4Pt12Sn25 type, ordered variant of the GdNi2.67Sn5.44. Stannides with magnetic rare earths (Nd, Gd, and Dy) are characterized by Curie–Weiss behaviour, whereas La4.87Ni12Sn24 is Pauli paramagnet in the temperature range 2–300 K. Their electrical properties were investigated by means of the electrical resistivity and Seebeck coefficient measurements in the temperature range 80–380 K. All investigated compounds exhibit metallic-like type of conductivity. Electronic structure calculations were also carried out to obtain the density of states (DOS) using the full potential linearized augmented plane wave (FLAPW) method for La4.87Ni12Sn24 and Dy4Ni12Sn25 compounds and confirmed the metallic type of conductivity.