Figure 2

Spin pumping experiment in various NM/Bi₂O₃ interface. Detected V/R spectrum of (a) Py/Ag/Bi₂O₃, (b) Py/Cu/Bi₂O₃; (c) Py/Au/Bi₂O₃ and Py/Au/Al₂O₃; (d) Py/Al/Bi₂O₃. The rf power-dependence of 5 samples is shown in the upper insets, and the angle-dependence of the normalized signal V/R is shown in the lower insets.