Phase Diagram of UPt₃ from Ultrasonic Velocity Measurements

Authors

Shireen Adenwalla, University of Nebraska-LincolnFollow
S. W. Lin, University of Wisconsin - Milwaukee
Q. Z. Ran, University of Wisconsin - Milwaukee
Z. Zhao, Northwestern University
J. B. Ketterson, Northwestern UniversityFollow
J. A. Sauls, Northwestern University
L. Taillefer, Centre de Recherches sur les Trés Basses Températures
D. G. Hinks, Argonne National Laboratory
M. Levy, University of Wisconsin - Milwaukee
Bimal K. Sarma, University of Wisconsin - Milwaukee

Date of this Version

1990

Citation

Physical Review Letters Volume 65, Number 18, October 1990

Abstract

We present measurements of longitudinal ultrasonic velocity on single crystals of the heavy-fermion superconductor UPt₃. The measurements show clear signatures of second-order phase transitions in the superconducting state, with the velocity anomalies well accounted for by Ginzburg-Landau theory. From these signatures we construct a phase diagram for UPt₃ that reveals all the boundary lines that have been identified as possible phase transitions. We are able to track the phase transition lines to a tetracritical point, located on the upper-critical-field curve, to within the width of the normal-superconducting transition.