Eur. Phys. J. B 5, 447-455 (1998)
https://doi.org/10.1007/s100510050465

Magnetic order and transport in the heavy-fermion system CeCu_6-xAu_x ^*

¹ Physikalisches Institut, Universität Karlsruhe, 76128 Karlsruhe, Germany
² Institut für Angewandte Physik, Technische Universität Dresden, 01062 Dresden, Germany
³ Institut für Theorie der Kondensierten Materie, Universität Karlsruhe, 76128 Karlsruhe, Germany

Received: 20 February 1998
Accepted: 17 April 1998
Published online: 15 October 1998

Abstract

We report on extensive elastic neutron scattering to determine the wave vector of the magnetic order in CeCuAu_x single crystals for x > 0.1. For all values of x investigated (0.2, 0.3, 0.5, 1.0) we find long-range incommensurate antiferromagnetic order with an ordering vector (0.625 0 0.275) for x=0.2, nearly unchanged for x=0.3, and (0.59 0 0) for x=0.5, staying roughly the same for x=1.0. In addition, short-range correlations are observed for x=0.2, reminiscent of those found previously for x=0.1. The ordered magnetic moment is found to increase rapidly for small x, and more slowly for the larger x values. The increase of the specific-heat anomaly at the ordering temperature with x is in qualitative accord with this behavior. Finally, data of the electrical resistivity for current flow along the three crystallographic directions are presented, showing a clear signature of the magnetic order. A theoretical interpretation of the interplay of magnetic order and transport in terms of (i) the partial suppression of the Kondo effect by the staggered magnetization and (ii) the anisotropic band structure induced by the staggered field is shown to account well for the data, provided the ordering vector is close to , where k_F is a typical Fermi momentum.