Interface studies on magnetron-sputtered SnO2-films

Thin SnO₂ films have been prepared for H₂-gas sensor application by RF magnetron sputtering onto different SiO₂ based glasses. ARXPS and sputter-AES measurements have been performed to evaluate the compounds at SnO₂-TiN-Au contacts as well as the depth-dependent composition at SnO₂-substrate-interfaces. A Tioxynitride compound has been identified as a boundary layer between SnO₂ and TiN. Enrichments of the substrate components Ba, B or Na have been percepted at the interface of SnO₂ and glass. These observations explain the activated interface conduction path by a strongly doped interdiffusion layer.     

Determination of intrinsic FMR line broadening in ferromagnetic (Fe44Co56)77Hf12N11 nanocomposite films

Ferromagnetic nanocomposite (Fe₄₄Co₅₆)₇₇Hf₁₂N₁₁ films were deposited to investigate their intrinsic damping mechanisms due to scattering of itinerant electrons, which carry the magnetic moment of the ferromagnetic transition elements. The films were produced by reactive r.f. magnetron sputtering using a 6 in. Fe₃₇Co₄₆Hf₁₇ target. They were annealed at 400 °C in a static magnetic field, in order to induce in-plane uniaxial anisotropy. Subsequently, the films can be considered as uniformly magnetised. A ferromagnetic resonance frequency (FMR) of around 2.3 GHz could be attained, which was determined by measuring the real and imaginary parts of the frequency dependent permeability up to 5 GHz. The imaginary part, which represents a typical resonance curve, was utilised to obtain its full-width at half-maximum Δf_eff (FWHM) for the total damping behaviour characterisation. Thereby, it is possible to extract the intrinsic Gilbert damping parameter α_int, which in turn can be decomposed into two additional damping terms α_sf and α_os allocated to “spin-flip” and “ordinary scattering”, respectively. This result is correlated and discussed in terms of a verified theoretic model, to identify whether damping due to spin-flip scattering and/or ordinary scattering is dominant.