Dresden 2009 – wissenschaftliches Programm

Bereiche | Tage | Auswahl | Suche | Downloads | Hilfe

TT: Fachverband Tiefe Temperaturen

TT 39: Correlated Electrons: Heavy Fermions 1

TT 39.9: Vortrag

Donnerstag, 26. März 2009, 12:00–12:15, HSZ 304

Normal state magnetoresistance in the heavy fermion superconductor CeCo(In_0.925Cd_0.075)₅ — •Sunil Nair¹, S. Wirth¹, M. Nicklas¹, A. D. Bianchi², Z. Fisk³, and F. Steglich¹ — ¹Max Planck Institute for Chemical Physics of Solids, 01187 Dresden, Germany. — ²Départment de Physique, Université de Montréal, Montréal, Quebec H3C 3J7, Canada. — ³University of California, Irvine, California 92697, USA.

The CeMIn₅ (where M: Co,Ir) family of heavy fermion systems is currently in vogue due to the delicate interplay between unconventional superconductivity and magnetism observed in these systems. A putative quantum critical point – which lies in the vicinity of the superconducting regime in the temperature-magnetic field phase space of these systems – manifests itself in a host of novel properties. An additional ambient pressure phase space was opened up by Cd substitution on the In site, which acts as an efficient electronic tuning agent and shifts the ground state from a superconducting to an antiferromagnetic one. Here, we present sensitive measurements of the magnetoresistance in the CeCo(In_0.925Cd_0.075)₅ system in the temperature range 0.05 K ≤ T ≤ 4 K and with magnetic fields of up to 15 T. At fields larger than the superconducting upper critical field, features corresponding to a possible destabilization of the antiferromagnetic order are observed. Measurements performed with the magnetic field applied along different crystallographic directions indicate that this feature is strongly anisotropic. The implications of our results are discussed in the context of the crystallographic and magnetic anisotropy of these systems.