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International audience; The crystalline and magnetic properties of micron thick magnetron sputtered Co1−x Crx and Co1−x Nix alloy films are analyzed in the view of their implementation as semi-hard magnets. All of the tested films crystallize in an hcp lattice, at least up to 35 at% of alloying elements (Cr or Ni). The structural study shows that the ratio of hcp phase with [0001] axis orientated perpendicular to the film as compared with in-plane orientation increases (resp. decreases), when Ni (resp. Cr) concentration increases independently of the post-annealing temperature. The orientation of the magnetization results from the competition between the demagnetization field which tends to align the magnetization in plane and the crystalline anisotropy which tends to maintain the magnetization along the [0001] axis. Interestingly, we find that, although Co and Ni are very similar atoms, Co1−x Nix alloys crystalline anisotropy can be strongly increased and reach up to twice the anisotropy of the best Co1−x Crx alloy, while maintaining a magnetization at saturation above 1200 kA/m. The thermal stability of the structural and magnetic properties of both alloys is demonstrated for an annealing temperature up to 300 °C.

International audience; • FeO films were synthesized by pulsed-DC magnetron sputtering from metallic target. • The film oxidation was controlled with a plasma emission monitoring system. • Special attention was paid to the sample position relative to the target axis. • Structural features depend on the oxidation rate of the growing films. • FeO behaviors are tuned from hematite semiconductor to magnetite semimetal properties. A R T I C L E I N F O Keywords: FeO Reactive sputtering Plasma emission monitoring Hematite Magnetite A B S T R A C T Iron oxide films were synthesized by pulsed-DC magnetron sputtering from a metallic target in Ar and O 2 gas mixtures. Plasma emission monitoring was implemented to accurately control the metal-to-oxygen ratio in the coating through the chemical state of the iron target. The intensity of the Fe* emission line was maintained at a given value (setpoint) by regulating the introduced oxygen flow rate. In addition, the oxidation rate of the growing film was adjusted by controlling the oxidation-to-deposition rate ratio as a function of the position of the substrates relative to the magnetron axis. The iron oxide films were characterized by X-ray diffraction, UV-VIS spectrophotometry, electrical measurement and vibrating sample magnetometry. In addition to the crys-tallization of pure hematite and magnetite phases, both phases coexist in a transition domain for a short range of setpoint depending on the oxidation-to-deposition rate ratio. The electrical, optical and magnetic behaviors of the FeO x films suggest that the relative proportion of phases can be tailored in this range. The FeO x film behaviors can then be tuned from the hematite semiconductor properties to the semi-metallic magnetite properties .

International audience; Fe-Ni-Si soft magnetic parts, using Ni coated high silicon steel powder, were manufactured by selective laser melting process. The type of defect changes from porosity to cracks and the relative density increases, from 50% to 99%, with the decreasing laser scanning speed. The microstructural analyses indicate that the low laser scanning speed fully melted the nickel coating and high-silicon steel core. The EBSD study showed that the separated island and lamellar mesostructures appeared on the top and side view respectively. Moreover, no apparent texture were observed. The magnetization saturation of SLM processed sample decreased, as the laser scanning speed was increased. Consequently, the magnetic properties of SLM processed Fe-Ni-Si alloy also showed anisotropic feature in building and scanning directions, which can be attributed to their different mesostructure.