Superconducting and ferromagnetic phase diagram of UCoGe probed by thermal expansion

AM Nikitin, JJ Geldhof, YK Huang, D Aoki, A De Visser - Physical Review B, 2017 - APS
Physical Review B, 2017APS
We report thermal expansion measurements on a single crystal of the superconducting
ferromagnet UCoGe for magnetic fields applied along the main orthorhombic axes. The
thermal expansion cell was mounted on a piezoelectric rotator in order to fine-tune the
magnetic field angle. The superconducting and magnetic phase diagram has been
determined. With our bulk technique we confirm the S shape of the upper-critical field, B c 2,
for B∥ b and reinforcement of superconductivity above 6 T. At the same time the Curie point …
We report thermal expansion measurements on a single crystal of the superconducting ferromagnet UCoGe for magnetic fields applied along the main orthorhombic axes. The thermal expansion cell was mounted on a piezoelectric rotator in order to fine-tune the magnetic field angle. The superconducting and magnetic phase diagram has been determined. With our bulk technique we confirm the shape of the upper-critical field, , for and reinforcement of superconductivity above 6 T. At the same time the Curie point shifts towards lower temperatures on increasing the field along the axis. This lends further support to theoretical proposals of spin-fluctuation-mediated reinforcement of superconductivity for .
American Physical Society