Crystal structure and specific heat of GdCuGe

摘要

A single crystal study of GdCuGe revealed full copper germanium ordering: NdPtSb type, space group P6(3)mc, a = 423.2(1), c = 753.7(2) pm, wR(2) = 0.0443, 414 F-2 values and 10 variables. The copper and germanium atoms build up two-dimensional networks of ordered [Cu3Ge3] hexagons with Cu-Ge distances of 244 put. Consecutive [Cu3Ge3] layers are rotated by 60 degrees around the perpendicular c-axis with respect to each other. The [Cu3Ge3] hexagons show a weak puckering. Heat capacity measurements on the polycrystalline sample of GdCuGe establishes antiferromagnetic ordering around 14 K in agreement with reports in the literature. The curves of heat capacity measured in different applied fields crosses each other at two well-defined points exhibiting a behavior usually associated with heavy fermion compounds. The results of the structural analysis and heat capacity measurements are discussed in the light of these interesting observations for a gadolinium intermetallic. (C) 2006 Elsevier Inc. All rights reserved.