Large Spin Hall Angle and Spin-Mixing Conductance in the Highly Resistive Antiferromagnet Mn2Au

Antiferromagnetic materials (AFMs) have recently been attracting interest in research on spintronics due to their zero stray magnetic field, high anisotropy, and spin-orbit coupling. In this context, the bimetallic AFMMn(2)Au has drawn attention because it exhibits unique properties and its Neel temperature is very high (T-N = 1500 K). Here, we report investigations of spin pumping and the inverse spin Hall effect (ISHE) in a Mn2Au/Co-Fe-B bilayer system using ferromagnetic resonance. We find a large spin Hall angle theta S-H = 0.22, with a spin Hall conductivity sigma(SH) = 1.46 x 10(5)(h/2e) Omega(-1) m(-1), comparable to that of Pt. Further, we evaluate the effective spin-mixing conductance g(eff)(down arrow up arrow) = 3.27 x 10(18) m(-2) and intrinsic spin-mixing conductance g(r)(up arrow down arrow) = 8.83 x 10(18) m(-2), which are higher than the previously reported value (1.40 x 10(18) m(-2) for Mn2Au/Y3Fe5O12).