Mn induced ferromagnetism spin fluctuation enhancement in Sr2Ru1−xMnxO4

We establish that Sr2RuO4 is extremely close to incommensurate spin density wave instability. With increasing Mn content, the RuO6 octahedron in the unit cell varies. The octahedron of RuO6 contracts along c-axis for x0.20), and Mn element shows the +4 chemical valence (Mn4+). Spin-glass-related ferromagnetism enhancement is observed for x>0.20, which indicates the critical ferromagnetic spin fluctuation due to Mn doping in Sr2Ru1−xMnxO4. •The chemical valence of Mn ions changed from Mn3+ to Mn4+ with the increase of Mn content.•Spin-glass-related ferromagnetism enhancement behavior is observed.•The electrical resistivity can be fitted using Mott's variable-range hopping model.•The evolution of octahedron with increase of Mn content is given.•The spin fluctuation effect plays an important role in the magnetic property.