Determination of spin pumping effect in CoFeB/Ir bilayer

•The spin diffusion length of Ir and the spin mixing conductance of CoFeB/Ir interface were obtained.•The spin mixing conductance is 2.14 × 1019 m−2 and the spin diffusion length is only 1.34 nm.•Ir possesses a strong spin-orbit coupling and is quite suitable for Ir-based spintronic materials engineering.