Search

CeCu 6− x Au x is known as a heavy fermion compound that exhibits antiferromagnetism for x ≳ 0 . 1 and non-Fermi-liquid (NFL) behavior around the critical concentration x c ≈ 0 . 1 . Although this material has been studied by means of a lot of experiments, the origin of its NFL is still veiled in mystery. In this study, we examine the magnetic properties of CeCu 6− x Au x for various values of x ( 0 ≤ x ≤ 0.8 ), and discuss the possibility that the quantum valence criticality might be responsible for the low-temperature magnetic properties. [ABSTRACT FROM AUTHOR]

Abstract: Elastic neutron scattering experiments on the pressure-induced ferromagnetic superconductor have been carried out under pressures P up to 1.6GPa at temperatures T down to 60mK, to study the correlation between superconductivity and ferromagnetism. No change was observed in ferromagnetic Bragg peak intensities nor a line width at through the superconducting transition temperature under and 1.25GPa, suggesting that the ferromagnetism is not affected by the onset of superconductivity under these two pressures. [Copyright &y& Elsevier]

We have measured ac magnetic susceptibility of the ferromagnet UGe2 which shows superconductivity in an external pressure range, P1⩽P⩽P2, in the ferromagnetic phase. When P is close to P1 (∼7 kbar in the present study) in the superconducting phase, the ac magnetic susceptibility indicates an imperfect superconducting shielding effect. It increases with pressure and shows nearly the perfect shielding effect around ∼12 kbar. We have also found that a superconducting onset temperature seems to be almost independent of the pressure below ∼12 kbar. [Copyright &y& Elsevier]