Scaling Behavior of the Spin Pumping Effect in Ferromagnet-Platinum Bilayers

Abstract

We systematically measured the dc voltage V(ISH) induced by spin pumping together with the inverse spin Hall effect in ferromagnet-platinum bilayer films. In all our samples, comprising ferromagnetic 3d transition metals, Heusler compounds, ferrite spinel oxides, and magnetic semiconductors, V(ISH) invariably has the same polarity, and scales with the magnetization precession cone angle. These findings, together with the spin mixing conductance derived from the experimental data, quantitatively corroborate the present theoretical understanding of spin pumping in combination with the inverse spin Hall effect.

Spin-charge coupled dynamics driven by a time-dependent magnetization

“…In this context, spin pumping [2][3][4][5] and the inverse spin Hall effect (ISHE) [5][6][7][8][9] are the tools of choice for generation and detection of electronic spin currents, respectively. The typical spin-pumping setup consists of a magnet/normal-metal bilayer [10].…”

Systematic variation of spin-orbit coupling withd-orbital filling: Large inverse spin Hall effect in3dtransition metals

“…Figure 2(i) plots the t Cr dependence of V ISHE /Rw, from which we obtain SD = 13.3 ± 2.1 nm by fitting to ISHE SD tanh C SD [25]. can be obtained from the spin-pumping enhancement of damping [9][10][11][12],…”

“…SHE depends on the SOC and θ SH is a measure of the strength of SOC. Because of the generally accepted Z 4 dependence of SOC, measurement of θ SH has been focused on heavy elements by SHE [8] or inverse spin Hall effect (ISHE) [9][10][11][12][13][14][15], while 3d metals have rarely been studied [16,17].…”

“…θ SH is a measure of SOC and can be calculated from [9,10,12,14], respectively, of the Cr layer, SD is the spin diffusion length of Cr, is the interfacial spin mixing conductance, P = 1.21 is a factor arising from the ellipticity of the magnetization precession [7], γ is the gyromagnetic ratio, h rf = 0.25 Oe is the rf field at P rf = 200 mW [7], and α is the Gilbert damping constant of YIG. To calculate θ SH , we first determine SD from the Cr thickness (t Cr ) dependence of V ISHE [ Fig.…”

Spin Orbit Coupling Controlled Spin Pumping and Spin Hall Magnetoresistance Effects

“…Functionality and performance of pure spin current devices strongly depend on the generation and detection approaches of spin current. Among various generation approaches 4-6 , the spin pumping has been widely used [6][7][8][9] , in which the spin current is produced in a heavy non-magnetic metallic (NM) layer when the magnetization precession of the neighboring ferromagnet (FM) layer is excited by the microwave magnetic field, as shown in Fig. 1(a).…”