F‐doped La_0.6Sr_0.4Co_0.2Fe_0.8O_3‐x−δF_x (LSCFFx, x = 0.05, 0.10, and 0.20) materials are evaluated as oxygen electrodes for solid oxide fuel and electrolyser cell application. Materials have been prepared via low‐temperature topotactic route by fluorination of the parent oxide with polyvinylidene fluorine (PVDF). A decrease in the polarisation resistance (R_p) is observed for the “LSCFFx” symmetric cells. However, the improved electrochemical behavior for the symmetric cells cannot be explained by the presence of fluorine, as post mortem chemical analysis shows that fluorine is absent from the materials after the calcination treatment, contradicting previous results from the literature and calling for deeper understanding. The presence of fluorine is proved to result in a sluggish surface exchange rate compared with the LSCF oxide via pulsed isotopic exchange technique. Despite the absence of fluorine in the fabricated symmetric cell, annealing with PVDF at low temperatures prior to the electrode fabrication is proven to be a beneficial step to improve the electrochemical performance of LSCF material with applications for solid oxide cells. Studies with room temperature X‐ray diffraction, X‐ray photoelectron spectroscopy, and Mössbauer spectroscopy suggest that increased oxygen vacancy concentration, structural disorder and changes in the cobalt/iron valence state distribution are potential explanations for the reduced R_p.

Nanocrystalline diamond NCD coatings could improve the performances of cutting tools if the adhesion on cobalt-cemented tungsten carbide WC–Co substrates was optimized and maintained during diamond deposit. In this study, a time modulated polarized growth process during diamond hot filament chemical vapor deposition (HFCVD) method was used. NCD coatings were deposited on cobalt-cemented tungsten carbide (WC–10% Co) substrates previously coated with tantalum or zirconium nitride–molybdenum bilayer as interlayer systems to control carbon and cobalt diffusion. Continuous films consisted of diamond clusters. Their size decreased when the applied bias voltage increased and substrate temperature decreased. Raman analyses confirmed the reduction of crystallite size and formation of nanocrystalline diamond films by time modulated biased substrate HFCVD process. Scratch tests showed that the NCD/interlayer systems/WC–10% Co displayed very good film adhesion interesting for cutting tools applications compared to NCD/WC–10% Co. In addition using an interlayer system could offer additional protection when diamond coating was deteriorated. This technique seems to be promising for industrial applications in the field of machining tools when increasing the thickness of the diamond layer by only extending the time modulated deposition process.

The combination of microplasma generation and optical multi-material fiber technologies enables real-time diagnostics. The stack-and-draw technique has emerged as a promising method for creating multimaterial fibers suitable for plasma-based diagnostics. The elaboration of such devices for the generation of long-lasting microplasma for real-time and remote analyses remains challenging due to the difficulties of reaching long lengths without defects and with continuous electrodes. Post-functionalization of the electrode surface is also required to increase the plasma emission duration. In this study, glass was preferred over polymers for producing rectangular fibers (ribbons) that are easy to stack without wasting space and are resistant to high operating temperatures. Conversely, an aluminum alloy was chosen for the electrodes to reduce discontinuity defects. With the chosen bi-electrode geometry, the cooling rate during drawing has to remain between 200 and 300 °C/s to limit defect formation and guarantee low electrical resistivity. During plasma generation, an in situ oxide layer forms on the tip of each electrode. This results in a significant increase in plasma emission duration without the need for an additional post-functionalization step after drawing. These ribbons were tested in combination with an optical emission spectrometer to create a miniature gas detector for hydrocarbons.