Spin Transport through the metallic antiferromagnet FeMn
We investigate spin transport through metallic antiferromagnets using measurements based on spin pumping combined with inverse spin Hall effects in Ni80Fe20/FeMn/W trilayers. The relatively large magnitude and opposite sign of spin Hall effects in W compared to FeMn enable an unambiguous detection of spin currents transmitted through the entire FeMn layer thickness. Using this approach we can detect two distinctively different spin transport regimes, which we associate with electronic and magnonic spin currents respectively. The latter can extend to relatively large distances (up to 9 nm) and is enhanced when the antiferromagnetic ordering temperature is close to the measurement temperature.