Crystalline Orientation–Dependent Spin Hall Effect in Epitaxial Platinum

We report on the spin Hall effect in epitaxial Pt films with well-defined crystalline (200), (220), and (111) orientations and smooth surfaces. The magnitude of the spin Hall effect has been determined by spin–torque ferromagnetic resonance measurements on epitaxial Pt/Py heterostructures. We observed a 54% enhancement of the charge-to-spin conversion efficiency of the epitaxial Pt when currents are applied along the in-plane <002> direction. Temperature-dependent harmonic measurements on epitaxial Pt/Co/Ni heterostructures compared to a polycrystalline Pt/Co/Ni suggest the extrinsic mechanism underlying spin Hall effect in epitaxial Pt. Our work contributes to the development of energy-efficient spintronic devices by engineering the crystalline anisotropy of non-magnetic metals.

Electroless Platinum Deposition Using Co3+/Co2+ Redox Couple as a Reducing Agent

In the present work, the kinetics of electroless deposition of Pt, using a cobalt ion redox system (Co3+/Co2+) as a reducing agent, has been investigated. The deposition rate of Pt depends on the pH, concentration of reactants, and temperature. The deaeration and bubbling of the plating solution with argon play an essential role. It was found that 0.11 mg cm−2 of Pt films could be deposited on the surface of a roughed glass sheet in one hour without replenishing the solution. Additional data have been obtained on the grounds of electrochemical quartz crystal microbalance experiments. The bubbling (agitation) of the electroless Pt plating solution with argon during the deposition of Pt results in a higher deposition rate and is ca. 3 µg cm−2 min−1. The Pt deposition rate is far less, and is as low as 0.14 µg cm−2 min−1 when the electroless Pt plating solution is not bubbled with argon during the deposition of Pt.

Магнитоиндуцированный нелинейно-оптический отклик плeнок на основе нанослоeв тяжeлых и ферромагнитного металлов

We present the results of the experimental studies of magnetization-induced effects in optical second harmonic generation (SHG) from three-layer W/Co/Pt films with different thicknesses of the cobalt layer (2-10 nm) influenced by longitudinal dc magnetic field. The intensity effect in the p-polarized second harmonic that is odd in magnetization was observed, which reveals an increase in the corresponding magnetic contrast of the SHG intensity with an increase of the cobalt layer thickness from 2 nm to 10 nm. A phenomenological description of the observed effects was carried out when considering the bulk nonlinear polarization at the SHG frequency, which is proportional to the magnetization gradient in the direction normal to the structure, as well as the interface contribution, which is proportional to the square of the magnetization of the films.