Figure 1

(a) A schematic representation of the device geometry (not to scale) and the measurement setup for the study of spin pumping and spin waves. A rectangular Py layer is patterned on top of a longer Pt section and is subsequently insulated using sputtered SiO${}_2$. ACPS lines are patterned on top of the SiO${}_2$. A signal generator (SG) is connected to one ACPS line, while the other is connected to a spectrum analyzer (SA). A voltmeter is connected across the Pt for measuring the spin-pumping signal. (b) Cross section of the device. The layer stack is Pt (10)|Ni${}_{81}$Fe${}_{19}$ (20)|SiO${}_2$ (30) (thickness is in nanometers). The bottom Pt is extended for making dc electrical contacts.Reuse & Permissions

Figure 2

The measured (open squares) and calculated (solid lines) values of the spin-wave power spectra ($P_{\mathrm{sw}}$) as a function of the precessional frequency ($f$) for various values of the applied bias field $H_b$.Reuse & Permissions

Figure 3

(a) The measured (open squares) and calculated (solid lines) values of the spin-pumping voltage ($V_{\mathrm{SP}}$) as a function of the precessional frequency ($f$) for various values of the applied bias field $H_b$. (b) The effective length ($A_{\mathrm{sc}}L$) used for quantifying the spin-pumping signal resulting from spin waves as a function of the precessional frequency.Reuse & Permissions

Figure 4

(a) A schematic cross section of the device used for measuring the voltage resulting from a homodyne AMR contribution of the precessional magnetization. It comprises an ACPS waveguide patterned on top of an insulated NiFe film, with electrical contact leads at the two ends of the NiFe. This device is present on the same wafer as the device shown in Fig. 1, and fabricated simultaneously, and hence all thicknesses and materials are exactly the same. (b) The measured spin-pumping signal from the device shown in Fig. 1 is plotted for an applied bias field of ${\mu }_0{H}_b$ $=$ 13.1 mT as open squares, while the measured AMR voltage from the device shown in Fig. 4a is plotted as open circles to show that there is no contribution of AMR in the present setup.Reuse & Permissions

Figure 5

A filled contour plot of the spin-pumping voltage as a function of the applied bias magnetic field ($H_b$) and frequency ($f$). A white solid line shows the calculated FMR frequency as a function of ${\mu }_0{H}_b$. The red dashed line shows the calculated surface wave frequencies. The measured frequencies resulting from the simultaneous spin-wave and spin-pumping measurements in Figs. 2 and 3a are shown as open squares.Reuse & Permissions

Figure 6

The amplitude of the measured spin-pumping signals shown in Fig. 5 is plotted as a function of the precessional frequency $f$ as solid squares. The amplitude of the calculated spin-pumping voltage as a function of $f$ due to both FMR and MSSW is plotted as a solid line. Also plotted by a dashed line is the contribution of the spin-pumping signal resulting from FMR only.Reuse & Permissions