The two-band spin diffusion model has been extended to nonequilibrium systems to investigate the recently discovered spin-Seebeck effect in a ferromagnetic metal. A calculation using this model well reproduces the experimental results for a Ni81Fe19 film; the gradient of electrochemical potential is different between up- and down-spin bands affected by a temperature difference between the ends of the film.

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The local vibration modes of N–H related defects in GaAsN are studied using isotopes. When GaAsN is grown through chemical beam epitaxy (CBE) using triethylgallium/tris(dimethylamino)arsenic/monomethylhydrazine gas, there are several local vibration modes (LVMs) in Fourier transform infrared (FTIR) spectra. Signals with stretching mode peaks at 2952, 3098, and 3125 cm−1 are reported, along with new wagging and stretching mode peaks at 960 and 3011 cm−1, which exist only in crystals grown through CBE. When the film is grown using deuterated MMHy as a nitrogen source, new peaks at 2206, 2302, 2318, 2245, and 714 cm−1 appear. This suggests that D related defects are created because of the deuterated MMHy. The ratios of frequencies of these new peaks to those obtained from crystals grown using MMHy are nearly 1.34. This suggests that all defects in GaAsN grown through CBE, which appear as LVMs, are N–H related defects. Especially, those with LVMs at 960 and 3011 cm−1 are new N–H defects only found in GaAsN grown through CBE.

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Ferromagnetic resonance spectra affected by the spin-Hall effect (SHE) and the spin torque were measured for a Ni81Fe19/Pd bilayer film. A charge current applied to the Pd layer is converted into a spin current via SHE, which propagates into the Ni81Fe19 layer through the interface as a spin current. The spin current exerts the torque on the magnetization, modulating the spin relaxation in the Ni81Fe19 layer. By monitoring the spin relaxation modulation, we estimated the spin current amplitude injected into the Ni81Fe19 layer. This method enables the quantitative measurement of spin currents without assuming any microscopic material parameters.