Heat capacity studies of Ce and Rh site substitution in the heavy fermion antiferromagnet CeRhIn_5: Short-range magnetic interactions and non-Fermi-liquid behavior
Abstract
In heavy fermion materials superconductivity tends to appear when long range magnetic order is suppressed by chemical doping or applying pressure. Here we report heat capacity measurements on diluted alloyes of the heavy fermion superconductor CeRhIn_5. Heat capacity measurements have been performed on CeRh_1-yIr_yIn5 ( y≤ 0.10) and Ce_1-xLa_xRhIn5 (x≤ 0.50) in applied fields up to 90 kOe to study the affect of doping and magnetic field on the magnetic ground state. The magnetic phase diagram of CeRh_0.9Ir_0.1In5 is consistent with the magnetic structure of CeRhIn5 being unchanged by Ir doping. Doping of Ir in small concentrations is shown to slightly increase the antiferromagnetic transition temperature TN (T_N=3.8 K in the undoped sample). La doping which causes disorder on the Ce sublattice is shown to lower T_N, with no long range order observed above 0.34 K for Ce_0.50La_0.50RhIn_5. Measurements on Ce_0.50La_0.50RhIn5 show a coexistence of short range magnetic order and non-Fermi-liquid behavior. This dual nature of the Ce 4f-electrons is very similar to the observed results on CeRhIn5 when long range magnetic order is suppressed at high pressure.
- Publication:
-
APS March Meeting Abstracts
- Pub Date:
- March 2004
- Bibcode:
- 2004APS..MARA20004L