Spin-Charge Conversion in Fe/Au/Sb2Te3 Heterostructures as Probed By Spin Pumping Ferromagnetic Resonance

Large-area antimony telluride (Sb2Te3) thin films are grown by a metal organic chemical vapor deposition technique on 4 Si(111) substrates, and their topological character probed by magnetoconductance measurements. When interfaced with Fe thin films, broadband ferromagnetic resonance spectroscopy (BFMR) shows a clear increase of the damping parameter in Fe/Sb2Te3 when compared to a reference Fe layer, which may suggest the occurrence of spin pumping (SP) into Sb2Te3. Simultaneously, X-ray reflectivity and conversion electron Mossbauer spectroscopy evidence the development of a chemically and magnetically pure Fe/Sb2Te3 interface. However, by conducting SP-FMR, it is shown that no spin-to-charge conversion (S2C) occurs in Fe/Sb2Te3, while a clear SP signal develops by introducing a 5 nm Au interlayer between Fe and Sb2Te3, with a measured inverse Edelstein effect conversion efficiency of lambda(IEE) = 0.27 nm. The results shed some light on the correlation among the chemical-structural-magnetic properties of the Fe/Sb2Te3 interface, the broadening of the magnetic damping parameter as detected by BFMR, and the occurrence of S2C, as probed by SP-FMR.

Automated summary

Large-area antimony telluride (Sb2Te3) thin films were grown using metal organic chemical vapor deposition technique, and their interaction with Fe thin films resulted in an increase in the damping parameter, suggesting the occurrence of spin pumping. Introducing a 5 nm Au interlayer between Fe and Sb2Te3 led to the development of a spin pumping signal, indicating the absence of spin-to-charge conversion in Fe/Sb2Te3. This study sheds light on the correlation among the chemical-structural-magnetic properties of the Fe/Sb2Te3 interface.