This study deposited CrAlN coatings from Al₅₀Cr₅₀ targets using high-power impulse magnetron sputtering, with a focus on the effects of nitrogen content and substrate bias voltage on the deposition rate, microstructure, crystal orientation, residual stress, and mechanical properties of the coating. The nitrogen content was adjusted by varying the N₂/Ar flow ratio between 20% and 140%. Increasing the nitrogen flow rate during deposition led to corresponding decreases in the deposition rate and film thickness. X-ray diffractometer (XRD) analysis revealed that a low N₂/Ar flow ratio (40%) resulted in an face-centered cubic (FCC) phase. Bias voltage also had considerable influence on the residual stress and grain size. A refined grain structure and high internal stress resulted in hard CrAlN coatings. Among the various parameter combinations evaluated in this study, the highest hardness (35.4 GPa) and highest elastic modulus (426 GPa) were obtained using an N₂/Ar flow ratio of 100% and a bias voltage of −120 V.

This study developed a hydrothermal method for the growth of three types of zinc oxide (ZnO) nanostructures: nanorods, nanowalls and nanoflowers. The structures are produced at high densities with a high degree of uniformity on Al-coated SiO₂ substrates without the need for surfactant. Unlike the random distribution of ZnO nanoflowers reported in previous studies, the proposed method makes it possible to control the distribution of these structures along the grooves created by altering the growth rate of ZnO nanorods and nanowalls. The number of ZnO nanoflowers created in this manner depends on the concentration of solution (HMT: hexamethylenetetramine) and reaction time. Measurements of cathodoluminescence (CL), X-ray diffractometry (XRD), and SEM-EDS confirm that the resulting structures are pure ZnO with good crystallinity. We also investigated the optical properties of these ZnO nanostructures and propose a possible growth mechanism.