Stability and Morphology of vacancy clusters in MAX phases

SCK•CEN Mentor

Bonny Giovanni, gbonny@sckcen.be, +32 (0)14 33 31 98

Expert group

Microstructural and Non-destructive Analysis

SCK•CEN Co-mentor

Bakaev Alexander , abakaev@sckcen.be , +32 (0)14 33 30 89

Introduction

Advanced carbide materials are presently considered in nuclear industry. For example, SiC composites and MAX phases are considered for accident tolerant fuel cladding, coatings and even structural components. Presently, many international efforts are focused in the Horizon 2020 IL TROVATORE project to investigate the radiation tolerance of these classes of materials.

            In recent years, computational models have claimed an important role in understanding the mechanisms at work leading to the degradation of materials under irradiation. The phenomenon of radiation in materials is inherently a multi-scale problem: a flux of subatomic particles (neutrons) interacts with lattice atoms leading to the failure of macroscopic components. Given the different length- and time scales involved, multi-scale modelling techniques are used to simulate the damage mechanisms active at the different scales of the radiation process.

Objective

In the present internship, the stability and optimum morphology of vacancy clusters in the Cr2AlC and Ti2AlC MAX phases. The stability of each cluster configuration is assessed by evaluation of its binding energy. In turn, the binding energy is computed from density functional theory (DFT) calculations. The latter provides a computationally efficient scheme to solve Schrödinger’s many body eigenvalue problem.

            Presently, the binding energy between vacancy pairs in both MAX phases has been characterized and some essential difference are observed. The objective of the student is to explore – starting from the most stable di-vacancy configurations – several vacancy cluster configurations and identify the most stable morphology for each MAX phase. As such, the question whether vacancies form planar or compact clusters can be answered.

The minimum diploma level of the candidate needs to be

Academic bachelor

The candidate needs to have a background in

Chemistry , Physics , Mathematics

Estimated duration

1 Month