First-principles calculation on the stable structure and adhesive strength of Ni/Fe(100) or Cu/Fe(100) interfaces

The maintenance of the adhesion of material interfaces is important in many technological fields. In this paper, we performed first principles calculation to understand the stable structure and adhesive strength of metallic material interfaces, Ni layer or Cu layer on Fe(100) surface formed by metal plating. In order to confirm the accuracy of our calculation, we have calculated the total energy and the [100] Young's modulus of Fe, Ni or Cu single crystal, by taking the spin-polarization into account. It was found that the calculated result of the crystal structure and lattice constant of these metals agreed satisfactorily with the values determined by experiments. The calculated [1001 Young's modulus of Fe, Ni and Cu was 136.7 GPa, 173.7 GPa and 122.2 GPa, respectively. Furthermore, we have calculated the stable configuration of Ni atoms at Fe (100) surface. Ni atoms take the corresponding position to the bcc structure of Fe (100) substrate. Similar result was obtained for Cu atoms at Fe(100) surface. The stable structure of the interfaces of 5 Ni layer/5 Fe (100) layer was determined, which was supported by TEM analysis of plated Ni layer on Fe (100) surface. The calculation also showed that the strength of adhesion of the Ni/Fe (100) interface stronger than that of the Cu/Fe (100) interface.