Calculating Study on Properties of Al (111)/6H-SiC (0001) Interfaces

Abstract

The research elaborates on the mechanical properties at the Al (111)/6H-SiC (0001) interface based on the density functional theory. Because of the difference in atom category at the interface of 6H-SiC (0001), it takes the C-terminated interface and Si-terminated interface into account. As indicated by the gross energy computing results at the two interfaces, the C-terminated Al (111)/6H-SiC (0001) interface demonstrates a greater adhesion force than the Si-terminated counterpart. Throughout detailed analysis on the bonding mechanism, surface hybridization and charge transfer at the Al (111)/6H-SiC (0001) reaction interface, the research reveals its strong covalent characteristics. According to the comparative study on the ideal tensile strength and general stacking fault energy at varying cleavage surfaces, a conclusion can be fitly reached that the fracture at the Al (111)/6H-SiC (0001) interface is easily seen in Al-Al bonds in the Al matrix instead of C(Si)-Al bonds at the interface. Despite the greater adhesion energy of the C-Al bond than the Si-Al bond, Al-Al bonds close to the C-terminated Al (111)/6H-SiC (0001) interface easily fracture due to the low ideal tensile strength.