Anisotropy of magnetoresistivities in Sr₄ Ru₃ O ₁₀: Evidence for an orbital-selective metamagnetic transition

We have investigated magnetic field orientation dependences of intraplanar and interplanar magnetoresistivity [ρ_ab (B,φθ) and ρc (B,φθ)] for Sr₄ Ru₃ O₁₀, which exhibits a puzzling coexistence of ferromagnetism and metamagnetism. We find that ρ_ab (B,φ) exhibits a remarkable field-dependent ferromagnetic anisotropy below and above the metamagnetic transition field Bc while ρc (B,φ) displays anisotropy from spin polarization only when field is above Bc. These observations strongly support that the metamagnetic transition in Sr₄ Ru₃ O₁₀ is orbital selective.