Low Temperature Specific Heat of Polycrystalline {{UGe2}} at High Pressure

In UGe2, superconductivity in coexistence with ferromagnetism is observed in single crystal (Nature 406 (2000) 587; Phys. Rev. B 63 (2001) 144519) and polycrystalline samples (J. Phys. Condens. Matter 13 (2001) L759) just below the pressure pc$\approx$16kbar for which the Curie temperature TC drops to zero. We present measurements of the specific heat C in the range 0.1\textendash{}2.5K on polycrystalline samples up to 14.7kbar. The linear coefficient of the specific heat, $\gamma$=C/T, increases as a function of pressure and is the highest in the p-range where superconductivity is observed. In the superconducting state the AC magnetic susceptibility exhibits strong diamagnetic shielding. The specific heat displays an anomaly that is indicative of a bulk superconducting transition of order 15\textendash{}20% by volume. The observed properties reflect an intricate interplay of the coexistence of ferromagnetism and superconductivity in UGe2.     «

In UGe2, superconductivity in coexistence with ferromagnetism is observed in single crystal (Nature 406 (2000) 587; Phys. Rev. B 63 (2001) 144519) and polycrystalline samples (J. Phys. Condens. Matter 13 (2001) L759) just below the pressure pc$\approx$16kbar for which the Curie temperature TC drops to zero. We present measurements of the specific heat C in the range 0.1\textendash{}2.5K on polycrystalline samples up to 14.7kbar. The linear coefficient of the specific heat, $\gamma$=C/T, increas...     »