Study of the hybrid state of Y9Co7(2.0≲T≲ 6 K) by means of zero field muon spin relaxation

Muon spin relaxation functions were measured in the magnetic superconductor Y 9 Co 7 for T ≳ 2.0 K and at zero applied field. In the paramagnetic region ( T ≳ 6.0 K) the depolarization of the muon spins is due to the quasi-static 59 Co nuclear moments. The onset of the magnetic state results in a fast-relaxing signal that corresponds to dipolar fields of the order of 100 0e; this component grows steadily in amplitude as the material transists from the hybrid into the superconducting state. The data are consistent with the high degree of inhomogeneity of the (not long-range) ordering and coexisting but non-competing magnetic and superconducting properties in the “hybrid” state (2< T <5K).