Effect of interfacial oxidation layer in spin pumping experiments on Ni80Fe20/SrIrO3 heterostructures

Abstract

SrIrO3 with its large spin–orbit coupling and low charge conductivity has emerged as a potential candidate for efficient spin–orbit torque magnetization control in spintronic devices. Here we report on the influence of an interfacial oxide layer on spin pumping experiments in Ni80Fe20 (NiFe)/SrIrO3 bilayer heterostructures. To investigate this scenario, we have carried out broadband ferromagnetic resonance (BBFMR) measurements, which indicate the presence of an interfacial antiferromagnetic oxide layer. We performed in-plane BBFMR experiments at cryogenic temperatures, which allowed us to simultaneously study dynamic spin pumping properties (Gilbert damping) and static magnetic properties (such as the effective magnetization and magnetic anisotropy). The results for NiFe/SrIrO3 bilayer thin films were analyzed and compared to those from a NiFe/NbN/SrIrO3 trilayer reference sample, where a spin-transparent, ultra-thin NbN layer was inserted to prevent the oxidation of NiFe. At low temperatures, we observe substantial differences in the magnetization dynamics parameters of these samples. In particular, the Gilbert damping in the NiFe/SrIrO3 bilayer sample drastically increases below 50K, which can be well explained by enhanced spin fluctuations at the antiferromagnetic ordering temperature of the interfacial oxide layer. Our results emphasize that this interfacial oxide layer plays an important role for the spin current transport across the NiFe/SrIrO3 interface.

Growth optimization of TaN for superconducting spintronics

“…4(a) is very similar for both samples and, moreover, is in agreement to a previous study on Py films capped with a thin insulating TaN-layer 49 . The observed reduction in α(T ) with decreasing T down to T = 100 K in both samples is compatible with previous results obtained for Py thin films 32,48,50 . For sample A, we observe an increase in α from 100 K to 5 K, while TaN is in the NC state.…”

“…The frequency evolution of the FMR linewidth µ 0 ∆H(f ) is fitted with the linear model to extract the Gilbert damping parameter α and the inhomogeneous broadening µ 0 H inh 32 . In this work, we are primarily interested in the temperature dependence of the Gilbert damping α(T ) as it is sensitive to spin pumping across the interface α = α 0 + α SP , where α 0 is the intrinsic damping and α SP denotes the additional dissipation channel for angular momentum via spin pumping 47,48 . For completeness, we present the temperature dependence of the remaining characteristic parameters describing the FMR in section V of the SM 37 .…”

Evaluation of Sputtering Processes in Strontium Iridate Thin Films

“…Furthermore, the literature about unexpected SIO-113 electronic properties, including strange metallicity [11,12] or the anomalous or topological Hall effect, is large [13][14][15]. On the other hand, due to its large spin-orbit coupling, it has also been employed in heterostructures for spin torque or spin-to-charge conversion experiments [16][17][18][19][20].…”