Multiple magnetic transitions and anomalous magnetism in Tb₂CuGe₃

Abstract

We report the formation of a compound, Tb₂CuGe₃, in a AlB₂-derived hexagonal structure and its magnetic characteristics by electrical resistance (1.4-300 K), magnetization (2-300 K) and heat-capacity (2-50 K) measurements. The results establish that there is an onset of antiferromagnetic ordering at a temperature close to 19 K, which is much larger than the de Gennes scaled value. The data also present evidence for additional magnetic transitions at lower temperatures, say at about 13 and 8 K, which also appear to be of antiferromagnetic type, however, with possible differences in the Fermi surfaces/magnetic structure. These results characterize that this compound is an interesting magnetic system.