We report the thermodynamic, magnetic, and electronic transport properties of the ternary intermetallic system orders antiferromagnetically at 0.95 K, while the nonmagnetic compound is a conventional 3.3-K superconductor. Kondo lattice effects appear to limit the entropy associated with the Néel transition to as an electronic contribution to the specific heat of is observed at roughly 35% of this γ survives the ordering transition. Hall effect, thermoelectric power, and ambient-pressure resistivity measurements confirm this interpretation. These results suggest that RKKY and Kondo interactions are closely balanced in this compound Contrary to expectations based on the Doniach Kondo necklace model, applied hydrostatic pressure modestly enhances the magnetic ordering temperature with As such provides a counterexample to Kondo systems with similar Kondo and RKKY energy scales, wherein applied pressure enhances at the expense of the ordered magnetic state.
- Received 9 April 2001
- Revised 17 July 2001
- Published 29 November 2001
© 2001 The American Physical Society