Atomistic study of structure and stability of thin Ni films on Fe surfaces

Abstract

The adhesion and residual strain of Ni thin-film coatings on γ-Fe and α-Fe substrates are investigated by ab initio calculations using density functional theory (DFT) in the local density approximation (LDA), and by an empirical Finnis–Sinclair type interatomic potential utilizing angle dependent terms. The results from the DFT and empirical potentials agree for strained coherent interfaces. The phase stability and structural transitions are studied for incoherent interfaces via molecular dynamics and static relaxation methods. It is found that the transition in thin Ni films from bcc to fcc structure occurs for three or four monolayers and is accompanied by a reorientation of the Ni film with respect to the Fe substrate.

Keywords:

• bonding
• density-functional theory
• molecular dynamic simulations
• structural transitions
• thin films

Acknowledgements

We gratefully acknowledge the financial support from the German Research Foundation DFG, Grant no. GU367/24-1, and from the German Federal Ministry for Education and Research BMBF, Grant nos. 03X0511 and 01R105273. We would like to thank Yuri Mishin for providing to us with the interatomic potential 8 used in this work.

Notes

†Current address: Technische Universität Darmstadt, Center of Smart Interfaces, Computational Methods, Petersenstraße 32, 64287 Darmstadt.

Additional information

Notes on contributors

Pim Schravendijk†

†Current address: Technische Universität Darmstadt, Center of Smart Interfaces, Computational Methods, Petersenstraße 32, 64287 Darmstadt.