Magnetic and Structural Characteristics of Lanthanide—Nickel Compounds

Abstract

The magnetic and structural characteristics of 11 intermetallic compounds represented by the formula LnNi are reported. The five compounds with Ln=Dy, Ho, Er, Tm, and Y are isomorphous and occur in the FeB structure. The others, with Ln=Ce, Pr, Nd, Sm, Gd, and Tb, form in the CrB structure, YNi and CeNi exhibit only Pauli paramagnetism down to 4.2°K. The others order magnetically with Curie temperatures ranging from 8°K for TmNi to 71°K for GdNi. Nickel appears to be nonmagnetic in the series and CeNi is nonmagnetic and hence Ce is quadripositive in CeNi. Curie—Weiss behavior is obeyed in the paramagnetic region for the compounds containing a magnetic Ln atom, except for TmNi, which exhibits a tendency toward Van Vleck‐type temperature‐independent paramagnetism at low temperatures. This and the fact that the observed saturation moments are well below the free tripositive lanthanide ion moments suggests that appreciable crystal field quenching of the orbital contribution occurs in these compounds. Except for TmNi, effective moments in the paramagnetic region are as expected for the free tripositive ions.