Improving the wettability of Ag/ZrB2 system by Ti, Zr and Hf addition: An insight from first-principle calculations

Abstract

The addition of active elements is an excellent method to improve the wettability and interfacial bonding strength between Ag and ZrB2. To quantitatively evaluate the interfacial behavior and structure stability of Ag (1 1 1)/ZrB2 (0 0 0 1) interface, the role of Ti, Zr and Hf additions in the interfacial bonding strength and electronic properties was investigated comprehensively by first-principle calculations. The B-terminated ZrB2 (0 0 0 1) surface is more active than the Zr-terminated surface under the lower B chemical potential. For the Ag (1 1 1)/ZrB2 (0 0 0 1) interface, the interface with center-site presents the largest work of adhesion (Wa) and the lowest interfacial energy for both Zr- and B-terminations. The Ti, Zr and Hf additions can greatly improve the Wa for Ag/ZrB2 interface (especially with the B-termination) when the Ag atom in 1st layer of Ag slab is substituted by active elements. The calculation on the electronic structure shows that the ionic bonding across Ag/ZrB2 interface is further enhanced while adding the active elements due to the strong interactions between the active elements and the closest B atomics. These results provide crucial fundamental insights to enhance the wettability of Ag/ZrB2 system by the addition of active elements.