Design of α-Al2O3/Cr2O3 nano-multilayered composite films with enhanced irradiation tolerance prepared by epitaxial growth at low temperature

In this paper, α-Al2O3/Cr2O3 nano-multilayered composite films were studied due to excellent properties of α-Al2O3 and template effect of Cr2O3 for the synthesis of α-Al2O3 at low temperature. SRIM code was used to simulate the irradiation damage of α-Al2O3/Cr2O3 multilayer films with different single layer thicknesses caused by 60 keV He+, in order to find out a better design of the structure of the multilayer film. α-Al2O3/Cr2O3 nano-multilayered films with different single layer thickness were deposited by RF magnetron reactive sputtering on Si (100) at 400 °C with Cr2O3 layers as crystallographic templates. The films were injected by 60 keV He+ with fluences of 0.5 × 1017, 1 × 1017 and 2 × 1017 He+/cm2 at temperature about 573 K to study the microstructural development and surface morphology evolution of α-Al2O3/Cr2O3 nano-multilayer films. The simulation results along with the SEM investigation indicated that to obtain better irradiation tolerance, one should design a multilayer with a high proportion of α-Al2O3 and more interfaces. The experimental results showed that the microstructures of the α-Al2O3 (100 nm)/Cr2O3 (60 nm) multilayers were nano-polycrystalline and remained stable even as the radiation fluences increase to 1 × 1017 He+/cm2. This suggests the excellent irradiation tolerance of α-Al2O3 (100 nm)/Cr2O3 (60 nm) nano-multilayered composite films.