Abstract
We report measurements of the specific heat of the heavy-fermion compound under hydrostatic pressure p up to 4.5 kbar. The two superconductive transitions at temperatures and observed previously under zero pressure decrease at a rate of /dp=-24 mK/kbar and /dp=-5 mK/kbar. The transitions merge at =3.7 kbar and =419 mK. These results suggest that the weak antiferromagnetic order, which is suppressed on the same pressure scale, acts as a symmetry-breaking field in splitting the superconductive transition, thus yielding convincing evidence for a non-BCS order parameter for this system.
- Received 25 March 1991
DOI:https://doi.org/10.1103/PhysRevB.43.13714
©1991 American Physical Society