Skyrmion imaging and electrical detection via topological Hall (TH) effect are two primary techniques for probing magnetic skyrmions which hold promise for next-generation magnetic storage. However, these two kinds of complementary techniques have rarely been employed to investigate the same samples. We report the observation of nanoscale skyrmions in SrIrO3/SrRuO3 (SIO/SRO

Low-loss magnetization dynamics and strong magnetoelastic coupling are generally mutually exclusive properties due to opposing dependencies on spin-orbit interactions. So far, the lack of low-damping, magnetostrictive ferrite films has hindered the development of power-efficient magnetoelectric and acoustic spintronic devices. Here, magnetically soft epitaxial spinel NiZnAl-ferrite thin films with an unusually low Gilbert damping parameter (<3 × 10 ), as well as strong magnetoelastic coupling evidenced by a giant strain-induced anisotropy field (≈1 T) and a sizable magnetostriction coefficient (≈10 ppm), are reported. This exceptional combination of low intrinsic damping and substantial magnetostriction arises from the cation chemistry of NiZnAl-ferrite. At the same time, the coherently strained film structure suppresses extrinsic damping, enables soft magnetic behavior, and generates large easy-plane magnetoelastic anisotropy. These findings provide a foundation for a new class of low-loss, magnetoelastic thin film materials that are promising for spin-mechanical devices.

B20 phase magnetic materials have been of significant interest because they enable magnetic Skyrmions. One major effort in this emerging field is the stabilization of Skyrmions at room temperature and zero magnetic field. We grow phase-pure, high crystalline quality FeGe epitaxial films on Si(111). Hall effect measurements reveal a strong topological Hall effect after subtracting the ordinary and anomalous Hall effects, demonstrating the formation of high density Skyrmions in FeGe films between 5 and 275 K. In particular, a substantial topological Hall effect was observed at a zero magnetic field, showing a robust Skyrmion phase without the need of an external magnetic field.

We measure the spin Hall angle in Au layers of 5 to 100 nm thicknesses by spin pumping from Y 3 Fe 5 O 12 epitaxial films grown by ultrahigh vacuum, off-axis sputtering. We observe a striking increase in the spin Hall angle for Au layers thinner than the measured spin diffusion length of 12.6 nm. In particular, the 5 nm Au layer shows a large spin Hall angle of 0.087, compared to those of 0.016 and 0.017 for the 50 and 100 nm Au layers, respectively, suggesting that the top surface plays a dominant role in spin Hall physics when the spin current is able to reach it. Other spin pumping related parameters, including Gilbert damping enhancement, interfacial spin mixing conductance, and spin current are also determined for Au layers of various thicknesses.Given the pervasive role ultrathin films in electrical and spin transport applications, this result emphasizes the importance of considering the impact of the top surface and reveals the possibility of tuning critical spin parameters by film thickness. PACS: 72.25.Ba, 76.50.+g, 72.25.Mk, 75.70.Ak 2The spin Hall effect (SHE) and its reciprocal process, the inverse spin Hall effect (ISHE), have generated intense interest in recent years as a means of producing, manipulating, and detecting spin currents in nonmagnetic materials, opening new routes to spin-based electronic applications.1-13 The ability to convert an unpolarized electrical current into a spin current can be quantitatively described by the spin Hall angle (θ SH ).14,15 θ SH is a material-specific quantity that arises from spin-orbit coupling (SOC). Its magnitude and sign are primarily determined by atomic number, and for transition metals, by the d-orbital filling. [16][17][18][19] Au is a transition metal with a large atomic number of 79, which should lead to strong SOC and hence a large θ SH . As a result, both SHE and ISHE in Au have been extensively studied by various techniques. 20-28These studies have reported values of θ SH for Au between 0.25% (0.0025) and 11% (0.11 during film growth and the substrate rotates at 10 degrees/sec to achieve optimal film uniformity.A radio-frequency power of 60 W is used for YIG sputtering, which gives a deposition rate of 0.51 nm/min. The Au is grown in-situ on the YIG film at room temperature by off-axis DC sputtering at a deposition rate of 2.24 nm/min. The crystalline quality of the YIG films and YIG/Au bilayers are examined by X-ray diffraction (XRD) and X-ray reflectivity (XRR) using a 3 Bruker D8 Discover high-resolution triple-axis X-ray diffractometer, and scanning transmission electron microscopy (STEM) using an FEI probe-corrected Titan 3 80-300 S/TEM. where e is the electron charge, σ Au is the Au conductivity, λ SD is the spin diffusion length in Au, is the effective interfacial spin mixing conductance, L is the sample length, P = 1.21 is a factor due to the ellipticity of magnetization precession, 5 γ is the gyromagnetic ratio, h rf = 0.25Oe is the rf magnetic field in the EPR cavity at P rf = 200 mW, and α is the Gilbert damping constant of ...

We report an approach to controlling the effective magnetization (Meff), a combination of the saturation magnetization and uniaxial anisotropy, of the ferrimagnet Y3Fe5O12 (YIG) using different species of ions: He+ and Ga+. The effective magnetization can be tuned as a function of the fluence, with He + providing the largest effect. We quantified the change in effective magnetization through an angular dependence of the ferromagnetic resonance before and after irradiation. Increases in 4πMeff were observed to be as much as 400 G with only a 15% increase in Gilbert damping, α (from 8.2e-4 to 9.4e-4). This result was combined with a method for accurate ion pattering, a focused ion beam, providing a mechanism for shaping the magnetic environment with submicron precision. We observe resonance modes localized by ion patterning of micron-sized dots, whose resonances match well with micromagnetic simulations. This technique offers a flexible tool for precision nanoscale control and characterization of the magnetic properties of YIG.