Abstract
The report measurements of the upper critical field, , inclined at various angles with respect to the axis in the heavy-fermion superconductor U. The angular anisotropy observed near K cannot be explained quantitatively by presently available theoretical expressions which consider either isotropic or anisotropic pairing. In addition, we find that the anisotropy apparently disappears at mK, only to reemerge at lower temperatures with an opposite sense. We have also studied in the basal plane of this hexagonal crystal and find no angular dependence within the limits of our measurements.
- Received 2 June 1986
DOI:https://doi.org/10.1103/PhysRevLett.57.1259
©1986 American Physical Society