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N-doped ZnO thin films were deposited on 304L stainless steel through the pyrolysis of zinc acetate and ammonium acetate in different ratios at a temperature of 420 °C using metal organic chemical vapor deposition. Compositional and structural analyzes of the films were performed by using Rutherford backscattering spectroscopy and X-ray diffraction. The frictional behavior of the thin films and 304L stainless steel substrate was evaluated using a ball-on-flat configuration with reciprocating sliding under marginally lubricated and fully flooded conditions. Al alloy (2017) was used as ball counterface, while basestock synthetic polyalfaolefin oil (PAO10) without additives was used as lubricant. The flat and ball counterface surfaces were examined to assess the wear dimension and failure mechanism. Under marginally lubricated condition, N-doped ZnO thin films provided significant reduction in friction, whereas the films have minimal or no effect in friction under fully flooded condition. N-doped ZnO thin films showed a significant effect in protecting the ball counterface as wear volume was reduced compared with that of the substrate under the marginally lubricated condition. Under the fully flooded condition, with the exception of one of the films, the wear volume of the N-doped ZnO thin films ball reduced compared with that of the substrate. In all the ball counterfaces for N-doped ZnO thin films under both conditions, wear occurred through abrasive mechanism of various degrees or mild polishing. Thus, superfluous lubrication of N-doped ZnO thin films is not necessary to reduce friction and wear.

The synthesis and comprehensive analysis of nitrogen-doped zinc oxide thin films grown from a compound precursor of zinc acetate and ammonium acetate has been reported. The precursor was processed in different ratios of the zinc acetate-ammonium acetate additives, and each combination was used to deposit a thin film using metalorganic chemical vapour deposition (MOCVD) method. The produced thin films were characterised using Rutherford backscattering (RBS) spectroscopy, uv-visible spectrometry, x-ray diffractometry, four point probe measurements and optical microscopy. The deposited thin films showed a fairly consistent zinc:oxygen:nitrogen ratio of 4.4:3.7:1, the film structures were quasicrystalline and the sheet resistivities were high, while other familiar characteristics like optical transmittance, bandgap, thermal stability, etc. were maintained in the grown films. Applications in device fabrication and active sensor devices were hence envisaged as the emergent potentials of the thin films.

The corrosion inhibition of Aluminium alloy AA8011 in 0.25 M hydrochloric acid solution by Rosmarinus officinalis L. (rosemary) leaves extract was studied using the gravimetric technique at 303, 313, 323 and 333K, and in the presence of an external magnetic field. The study reveals that the methanolic extract of rosemary leaves inhibits corrosion of Al in 0.25 M HCl. The inhibition efficiency was found to increase with increase in concentration of the extract, but decreased with increase in temperature. Thermodynamic activation parameters like the activation energy (E a ), ranged from 15.29 to 35.06 kJ/mol, thereby suggesting the mix mechanism of physichemisorption; calculated values of the standard adsorption enthalpies () o ads H  were positive indicating an endothermic process, while negative values of entropies () o ads S  implied an associative interaction between the inhibitor molecules and the Al surface. The corrosion data was found to be a good fit for the Langmuir (R 2 > 0.98) and Villamil (R 2 > 0.99) isotherm models. Values of the adsorption free energy () o ads G obtained were negative, thereby describing a spontaneous adsorption process. The effect of an external magnetic field was found to have a mixed behaviour in the presence of the R. offinalis L. extract at room temperature. Nonetheless, the corrosion rate was generally found to decrease with increase in strength of the magnetic field.