Spin current transmission in Co1-xTbx films

We investigate the spin to charge conversion phenomena in Y₃Fe₅O₁₂/Pt/Co_1-xTb_x/Pt multilayers by both the spin pumping and spin Seebeck effects. We find that the spin transport efficiency is irrelevant to magnetization states of the perpendicular magnetized Co_1-xTb_x films, which can be attributed to the symmetry requirement of the inverse transverse spin Hall effect. Furthermore, the spin transmission efficiency is significantly affected by the film concentration, revealing the dominant role of extrinsic impurity scattering caused by Tb impurity. The present results provide further guidance for enhancing the spin transport efficiency and developing spintronic devices.