A novel direction of spintronics, namely "spin-orbitronics", exploits the spin-orbit coupling (SOC) to generate spin currents, which can then induce spin-orbit torques (SOT) to manipulate magnetization. [1] This opens technological applications such as the three-terminal magnetic random memory Spintronics exploit spin-orbit coupling (SOC) to generate spin currents, spin torques, and, in the absence of inversion symmetry, Rashba and Dzyaloshinskii-Moriya interactions. The widely used magnetic materials, based on 3d metals such as Fe and Co, possess a small SOC. To circumvent this shortcoming, the common practice has been to utilize the large SOC of nonmagnetic layers of 5d heavy metals (HMs), such as Pt, to generate spin currents and, in turn, exert spin torques on the magnetic layers. Here, a new class of material architectures is introduced, excluding nonmagnetic 5d HMs, for high-performance spintronics operations. Very strong current-induced torques exerted on single ferrimagnetic GdFeCo layers, due to the combination of large SOC of the Gd 5d states and inversion symmetry breaking mainly engineered by interfaces, are demonstrated. These "self-torques" are enhanced around the magnetization compensation temperature and can be tuned by adjusting the spin absorption outside the GdFeCo layer. In other measurements, the very large emission of spin current from GdFeCo, 80% (20%) of spin anomalous Hall effect (spin Hall effect) symmetry is determined. This material platform opens new perspectives to exert "self-torques" on single magnetic layers as well as to generate spin currents from a magnetic layer.

Recent demonstration of magnetization manipulation has been focused on the utilization of pure spin current converted by charge current in nonmagnetic materials with strong spin-orbit coupling (SOC), which stimulates intensive studies on the exploration of materials with larger SOC, such as heavy metals and topological insulators. We suggest an alternative approach for enhancing the effective charge-tospin conversion efficiency by applying strain in Ta/Fe/Pt films grown on flexible mica substrates. We experimentally demonstrate a large and tunable charge-to-spin conversion efficiency in Ta/Fe/Pt films by applying compressive strain within a flexible substrate, and over 50% enhancement of effective spin Hall angle eff SHE of up to approximately 0.2 is achieved in a 6.26‰ strained film. Our findings may spur further work on the integration of flexible electronics and SOC and may potentially lead to the innovation of alternative flexible spintronics devices.