Measurements of the exchange stiffness of YIG films using broadband ferromagnetic resonance techniques

Abstract

Abstract. Measurements of the exchange stiffness D and the exchange constant A of Yttrium Iron Garnet (YIG) films are presented. The YIG films with thicknesses from 0.9 µm to 2.6 µm were investigated with a microwave setup in a wide frequency range from 5 to 40 GHz. The measurements were performed when the external static magnetic field was applied in-plane and out-of-plane. The method of Schreiber and Frait [1], based on the analysis of the perpendicular standing spin wave (PSSW) mode frequency dependence on the applied out-of-plane magnetic field, was used to obtain the exchange stiffness D. This method was modified to avoid the influence of internal magnetic fields during the determination of the exchange stiffness. Furthermore, the method was adapted for in-plane measurements as well. The results obtained using all methods are compared and values of D between (5.18 ± 0.01) · 10 −17 T·m 2 and (5.34±0.02)·10 −17 T·m 2 were obtained for different thicknesses. From this the exchange constant was calculated to be A = (3.65 ± 0.38) pJ/m. arXiv:1408.5772v1 [cond-mat.mtrl-sci]

Spin-Torque Excitation of Perpendicular Standing Spin Waves in Coupled YIG/Co Heterostructures

“…3(a–c) show the simulated microwave signal |∂ D S 21 /∂ H | ∝ |∂ χ 1 /∂ H | (for details see S3, S9 [15]). For all simulations we take the same material parameters, namely μ 0 M s , 1 = 1.91 T, A = 3.76 pJ/m, α 1 = 7.7×10 −3 , α 2 = 7.2×10 −4 , γ 1 = 28.7 GHz/T and γ 2 = 27.07 GHz/T, as extracted in S4, S5, S7 [15], which are in good agreement with previous reports [26–29]. The thicknesses are d 1 = 50 nm and d 2 = 1 μ m. For the YIG saturation magnetization we take the literature value μ 0 M s , 2 = 0.18 T [30].…”

Frequency and magnetic field mapping of magnetoelastic spin pumping in high overtone bulk acoustic wave resonator

“…The pattern shown in Fig. 2 [25][26][27] and that H ex (q cr ) ≈ δH, one can obtain exchange stiffness constant D ≈ 5×10 -9 cm 2 Oe typical for YIG and magnetization 4πM s ≈ 900 G typical for (La,Ga)YIG. The same measurements in the reversal field display that only the voltage sign change takes place.…”

Temperature-dependent Brillouin light scattering spectra of magnons in yttrium iron garnet and permalloy

“…where is the gyromagnetic ratio of 28.0 GHz T , is the permeability of free space, is the anisotropy field of 1 mT 14 , is the calculated demagnetization factor along the applied field direction, is the exchange stiffness constant of 5.4 0.1 10 T m 27,28 , and is the saturation magnetization. The YIG sample is approximately 1.2 x 1.5 x 0.5 mm in size.…”