Mechanical and Electronic Properties of Al(111)/6H-SiC Interfaces: A DFT Study

A density functional theory (DFT) calculation is carried out in this work to investigate the effect of vacancies on the behavior of Al(111)/6H SiC composites. Generally, DFT simulations with appropriate interface models can be an acceptable alternative to experimental methods. We developed two modes...

Full description

Bibliographic Details
Main Authors: Mostafa Fathalian, Eligiusz Postek, Tomasz Sadowski
Format: Article
Language:English
Published: MDPI AG 2023-05-01
Series:Molecules
Subjects:
Online Access:https://www.mdpi.com/1420-3049/28/11/4345
Description
Summary:A density functional theory (DFT) calculation is carried out in this work to investigate the effect of vacancies on the behavior of Al(111)/6H SiC composites. Generally, DFT simulations with appropriate interface models can be an acceptable alternative to experimental methods. We developed two modes for Al/SiC superlattices: C-terminated and Si-terminated interface configurations. C and Si vacancies reduce interfacial adhesion near the interface, while Al vacancies have little effect. Supercells are stretched vertically along the z-direction to obtain tensile strength. Stress–strain diagrams illustrate that the tensile properties of the composite can be improved by the presence of a vacancy, particularly on the SiC side, compared to a composite without a vacancy. Determining the interfacial fracture toughness plays a pivotal role in evaluating the resistance of materials to failure. The fracture toughness of Al/SiC is calculated using the first principal calculations in this paper. Young’s modulus (<i>E</i>) and surface energy (Ɣ) is calculated to obtain the fracture toughness (<i>K<sub>IC</sub></i>). Young’s modulus is higher for C-terminated configurations than for Si-terminated configurations. Surface energy plays a dominant role in determining the fracture toughness process. Finally, to better understand the electronic properties of this system, the density of states (DOS) is calculated.
ISSN:1420-3049