Magnetic Characteristics of 2–17 Lanthanide-Nickel Compounds

Magnetic characteristics of nine compounds represented by the formula Ln2Ni17 (Ln=Y or a lanthanide) are reported. The Y, Sm, and Lu compounds are ferromagnetic; the others are ferrimagnetic. Curie temperatures range from 601° to 641°K. The nickel moment is 0.27 μB, which is in very close agreement with 0.25 μB, the value expected if all Ln valence electrons are transferred into the Ni 3d band. Magnetization of the Y2Ni17 and Lu2Ni17 compounds is lost in two stages as temperature is increased. Ferrimagnetism of heavy lanthanide compounds is indicated by the magnitude of their saturation moments and the form of the magnetization-temperature curves. The magnetic coupling is the same as that observed in similar and related Ln–Co and Ln–Fe compounds, i.e., the Ln–Ni coupling is antiferromagnetic and ferromagnetic for heavy and light lanthanides, respectively. From the Curie temperature it is inferred that the Ni–Ni interaction is dominant. This is in contrast with the situation in Ni-containing Laves and Haucke phases, in which the Ln–Ln interaction is dominant.