Transverse and Longitudinal Magnetic-Field Responses in the Ising Ferromagnets URhGe, UCoGe and UGe2

TL;DR

This study investigates how magnetic fields influence the electronic specific heat in ferromagnetic superconductors URhGe, UCoGe, and UGe2, revealing significant anisotropic responses linked to magnetic reorientations and implications for field-induced superconductivity.

Contribution

It provides the first detailed analysis of the field-dependent electronic specific heat in these ferromagnetic superconductors across different crystallographic directions.

Findings

Large gamma(H) enhancement at reorientational transition along the b axis

Rapid suppression of gamma(H) when fields are applied along the easy axis

Implications for understanding field-induced superconductivity in related materials

Abstract

The field dependence of the electronic specific heat gamma(H) of URhGe is determined using temperature-dependent magnetization measurements and Maxwell's relation for all three orthorhombic directions. A large (40 %) enhancement of gamma(H) is found at the reorientational transition for fields applied along the b hard axis, which we argue occurs when the field-induced moment is of the same size as the zero-field ordered moment M0. Fields applied along the easy direction, on the other hand, lead to a rapid suppression of gamma(H). We emphasize that this behavior is also applicable to the closely related ferromagnetic superconductors UCoGe and UGe2 and discuss implications for the novel field-induced/enhanced superconductivity in these materials.