Strain–order-parameter coupling and phase diagrams in superconductingUPt3

Abstract
We studied elastic constants, ultrasonic attenuation, and ac susceptibility in a high-quality single crystal of UPt3 in the superconducting phase. We investigated the coupling of strain and order parameter for the different elastic modes. A detailed B-T phase diagram for the superconducting phases obtained from elastic-constant measurements is given and compared with theoretical predictions.