Co2FeAl (CFA) thin films with thickness varying from 10 nm to 115 nm have been deposited on MgO(001) substrates by magnetron sputtering and then capped by Ta or Cr layer. X-rays diffraction (XRD) revealed that the cubic [001] CFA axis is normal to the substrate and that all the CFA films exhibit full epitaxial growth. The chemical order varies from the B2 phase to the A2 phase when decreasing the thickness. Magneto-optical Kerr effect (MOKE) and vibrating sample magnetometer measurements show that, depending on the field orientation, one or two-step switchings occur. Moreover, the films present a quadratic MOKE signal increasing with the CFA thickness, due to the increasing chemical order. Ferromagnetic resonance, MOKE transverse bias initial inverse susceptibility and torque (TBIIST) measurements reveal that the in-plane anisotropy results from the superposition of a uniaxial and of a fourfold symmetry term. The fourfold anisotropy is in accord with the crystal structure of the samples and is correlated to the biaxial strain and to the chemical order present in the films. In addition, a large negative perpendicular uniaxial anisotropy is observed. Frequency and angular dependences of the FMR linewidth show two magnon scattering and mosaicity contributions, which depend on the CFA thickness. A Gilbert damping coefficient as low as 0.0011 is found. arXiv:1305.0714v1 [cond-mat.mtrl-sci]

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In this paper, we investigate a new distributed antenna array PECVD system, with 16 microwave plasma sources arranged in a 2D matrix, which enables the growth of 4-inch diamond films using H 2 /CH 4 /CO 2 gas mixture at low gas pressure, typically below 0.45 mbar, and at substrate temperature of 400 8C. The influence of substrate position with respect to elementary microwave sources is investigated for three sets of gas pressures in order to improve the diamond growth process in this low temperature/large area deposition setup. Results show that the nanocrystalline diamond films are formed of polycrystalline globular aggregates of 50-200 nm in size, depending on growth conditions, composed of diamond grains around 10-20 nm. An optimal deposition condition corresponding to a pressure of 0.45 mbar and a distance between substrate and microwave sources of 65 mm can be found. In these conditions, highest growth rate (60 nm h À1 ) with good nanocrystalline features, i.e. smallest grain size (10 nm) and lowest roughness (around 15 nm), is obtained.

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