CuCr _0.93 Mg _0.07 O ₂ thin films with improved optoelectronic properties were deposited by reactive magnetron sputtering on fused quartz substrates. The influence of annealing temperature under vacuum on optoelectronic properties of the films was investigated. The amorphous films annealed under vacuum at temperatures higher than 923 K are single-phased delafossite structure, while impurity phases like CuCr ₂ O ₄ that affect the optoelectronic properties of the films are detected below 873 K. c -axis orientation is observed for CuCr _0.93 Mg _0.07 O ₂ layers and the annealing temperature window in which the films are single-phased delafossite is much larger with Mg doping (923 K → 1073 K) than that for undoped films (~953 K). The optical and electrical behaviours of the films are enhanced by Mg substitution and their direct band gap energy of about 3.12–3.14 eV is measured. The film possesses the optimum properties after annealing under vacuum at about 1023 K; its average transmittance in the visible region can reach 54.23% while the film’s conductivity is about 0.27 S cm ⁻¹ .

SnO₂ thin films were prepared by conventional and Glancing Angle Deposition reactive sputtering, and their gas sensing properties were investigated. The porosity of the as-prepared films was widely assessed using optical methods, and the sensing performances of these active layers were correlated with the evolution of surface and film porosity as a function of deposition conditions and annealing treatment. The sensor made of inclined columns grown at high sputtering pressure (6 × 10⁻³ mbar) and annealed at 500 °C in air exhibited the best response to benzene, with a limit of detection of 30 ppb. In addition, successful BTEX (i.e., benzene, toluene, ethylbenzene, and xylenes) discrimination was achieved by combining the sensing signals of four nanostructured tin-oxide-based gas sensors.

Metallic platinum–titanium coatings were deposited by co-sputtering of two metallic Pt and Ti targets in pure argon atmosphere. The titanium concentrations varied from 0 to 47 atomic percent and were adjusted as a function of the current applied to the titanium target. The structural and chemical features of these films were assessed by X-ray diffraction (XRD) and scanning electron microscopy (SEM). All as-deposited coatings exhibit a perfect covering of the alumina pellets’ substrate surface. The coatings containing more than 4 at.% Ti are amorphous, whereas the others crystallize in the face-centered cubic (fcc) structure of platinum. After an annealing treatment under air for 2 h, all of the coatings adopt the fcc structure with a crystallization temperature depending on the titanium content. For titanium concentrations higher than 32 at.%, the TiO₂ phase appears during the annealing treatment. For the smaller film thickness of Pt–Ti alloys (15 nm), the Ostwald ripening mechanism is observed by SEM increasing the annealing temperature regardless of the content of Ti. The film resistivity measured at room temperature is lower than 7 × 10⁻⁴ Ω·cm and increases with the temperature to achieve an insulating behavior (in air and reducing atmosphere Ar-H₂ (90-10) at 1123 K the resistivity is ρ ≈ 10⁺³⁶ Ω·cm). When the thickness of intermetallic Pt₃Ti layer is higher than 50 nm, the coating is continuous and the resistivity is below 5 × 10⁻⁴ Ω·cm in air and in reducing atmosphere (Ar with 10% of H₂) up to 1273 K.