• Vejpravová-Poltierová, J.; Pospísil, J.; Prokleska, J.; Prokes, K.; Stunault, A.; Sechovský, V.: Low magnetic field phase diagram of UCoGe. Physical Review B 82 (2010), p. 180517(R)/1-4

10.1103/PhysRevB.82.180517

Abstract:
We propose an alternate scenario for the relation between ferromagnetism FM and superconductivity SC in UCoGe at ambient pressure. On the basis of neutron polarimetry measurement performed in strictly zero field on a single crystal at ambient pressure, we claim that the SC phase does exist in spite of lack of long-range FM order. Moreover, the SC regime dominates to the paramagnetic state in small external magnetic fields. Above the critical SC temperature, TSC=0.64 K, the zero-field state is characterized by a regime with strong FM spin fluctuations, suggesting the proximity of the FM quantum-critical point.