Formation of cubic structured (Al1 − xCrx)2 + δO3 and its dynamic transition to corundum phase during cathodic arc evaporation

► Microstructure and electronic properties of AlCr-based oxide coatings were studied. ► The films crystallize in the B1 structure and then adopt the corundum one. ► Results indicate that the cubic layer acquires the properties of a metastable monoxide. ► There is a thickness-dependent chemical composition along the film thickness.