The magnetic properties of the quaternary intermetallic GdNi₂B₂C and GdNiBC compounds

Abstract

The magnetic features of GdNi2B2C (14/mmm, a=3.578 A, c=10.361 A) and GdNiBC (P4/nmm, a=3.631 A, c=7.546 A) have been studied for 1.2 K<T<300 K and in fields up to 140 kOe. In both types of compound, the spherical 8S State of the Gd3+ ion can be unambiguously observed in the features of the paramagnetic state as well as the low-T field-induced ferromagnetic state. The observed Neel points for GdNi2B2C and GdNiBC are, respectively, 19.5(5) K and 14.3(5) K, and their magnetic structures at T=0 are presumably the collinear Neel-type structures. The saturating field in GdNi2B2C (H>or=125 kOe at 1.7 K) is approximately three times that of GdNiBC implying that the average interlayer interactions in the former are much stronger than in the latter. The overall magnetic features of both compounds are interpreted in terms of the picture that assumes the Gd moments to have strong ferromagnetic intralayer couplings and averaged antiferromagnetic interlayer interactions.