A review of ultrasonic measurements on the three heavy fermion compounds UPt3, URu2Si2 and CeCu6 is given. These compounds show one or more of the three types of co-operative behavior; Kondo-like effect, antiferromagnetism and superconductivity; all these features are observed as ultrasonic anomalies. Both UPt3 and CeCu6 show a strong coherence effect which is akin to a Kondo-like transition in the electronic system. Velocity anomalies are found at the antiferromagnetic transition for URu2Si2. UPt3 also has an antiferromagnetic transition which is believed to influence the subsequent superconducting ordering. For UPt3, the superconductivity is of an unconventional nature; multiple superconducting phases have been observed and a complete phase diagram has been obtained from high resolution velocity measurements.
ASJC Scopus subject areas
- Atomic and Molecular Physics, and Optics
- Materials Science(all)
- Condensed Matter Physics