This study investigates the thermal decomposition of acetyl acetonates of Ni(II) and Fe(III) via a sonochemical process at 20 kHz for 50 min. In the absence of magnetic fields the reactions of Ni(II) and Fe(III) acetyl acetonates under ultrasonic treatment produce Ni(OH)₂ and FeO(OH) nanoparticles coated with carbon. The synthesized materials with different Ni-Fe stoichiometries, Ni90-Fe10, Ni80-Fe20, and Ni50-Fe50 wt%, were subjected to catalytic activity for dye decolorization of Reactive Black 5 (RB5, 100 mg/L) at room temperature using visible radiation. The correlation between the structural and optoelectronic properties and the catalytic performance of the Ni-Fe system with different stoichiometries is reported.

In the present work, Cr/Cr₂O₃ thin films were applied on 304L stainless steel substrates via modulated pulsed power magnetron sputtering to investigate their protective behaviour against metal dusting for this steel. Depositions of the films were carried out at various negative values of bias voltage. The structure of the films consisted of a very dense fine columnar structure composed of textured Cr₂O₃. The films showed similar, very good protective behaviour during exposition to an atmosphere of CH₄+H₂+residual oxygen and moisture at 1073 K for 20 h. The main protection mechanism proposed was associated to the coatings acting as barriers for outward diffusion of the alloy elements and inward diffusion of C and O into the alloy, especially early in the exposure.