Thermal expansion of CeCU6-xAux

CeCu6-xAux orders antiferromagnetically for x > 0.1. The ordering wave vector changes drastically between x = 0.4 and 0.5, while the Neel temperature T-N(x) varies linearly between x = 0.1 and 1.0. The linear thermal expansion coefficient alpha shows for x = 0.3 a positive jump Deltaalpha(a) while Deltaalpha(b) and Deltaalpha(c) < 0. When increasing x to x = 0.5, Deltaalpha(a) and Deltaalpha(b) change sign, apparently reflecting the underlying change of the magnetic ordering wave vector. (C) 2003 Elsevier B.V. All rights reserved.