Diamond(001)-Si(001) and Si(001)-Ti(0001) interfaces: A density functional theory study

Peeling is considered to be the main technical obstacle for coating applications. There are many factors that affect the peeling process of coatings. The interfacial properties of the coating and substrate play a crucial role in the peeling process. In this study, the work of adhesion (W-ad), interface energy (gamma i), and electronic structure of diamond (001)-Si(001) and Si(001)-Ti (0001) interface models have been investigated using first-principles calculations. The results indicate that the diamond (001)-Si(001) interface exhibits larger W-ad and smaller gamma i values when compared with the Si(001)-Ti (0001) interface. However, the W-ad of diamond-diamond, Si-Si, and Ti-Ti is 15.92, 4.92, and 3.84 J/m(2), respectively. When compared with the two interface models, the W-ad of Ti-Ti is the smallest, indicating that it will be the first to undergo deformation during the shear process. In addition, analysis of the charge density difference and density of states revealed that the interfacial Ti-Si bond is a covalent-metallic bond, which is much weaker than the Si-C bond (covalent bond), and therefore, the Si(001)-Ti (0001) structure is more inclined to delaminate.

Automated summary

The study investigated the peeling process of coatings by using first-principles calculations to analyze the work of adhesion, interface energy, and electronic structure. Results showed that the diamond-Si interface exhibited better performance, while the Ti-Ti interface was most prone to deformation, and the Si-Ti interface was more likely to delaminate.