Adhesion at a heterophase interface: First-principles study of Mo(001)/MoSi 2 (001)

Abstract

The bonding characteristics, interfacial energetics, and electronic structure associated with adhesion at the Mo-MoSi 2 (001) heterophase interface are investigated using the first-principles, self-consistent local orbital method. We found both the adhesive energy and peak interfacial strength for the interface to be 10%-15% smaller than the respective values for cleavage along the (001) planes in crystalline Mo and MoSi 2 . The equilibrium interlayer separation between Mo and MoSi 2 is found to lie between the interplanar spacings of crystalline Mo and MoSi 2 . The interfacial adhesive bonding is attributable to the combination of a nearly uniform band of charge accumulation at the interface and directional charge accumulation between atoms across the interface. These first-principles calculations demonstrate that the universal-binding-energy relation can be extended to describe adhesion between dissimilar materials.