Microscopic Modeling of Interfaces in Cu-Mo Nanocomposites: The Case Study of Nanometric Metallic Multilayers

Nanocomposites composed of Cu and Mo were investigated by means of molecular dynamics (MD) simulations to study the incoherent interface between Cu and Mo. In order to select an appropriate potential capable of accurately describing the Cu-Mo system, five many-body potentials were compared: three Embedded Atom Method (EAM) potentials, a Tight Binding Second Moment Approximation (TB-SMA) potential, and a Modified Embedded Atom Method (MEAM) potential. Among these, the EAM potential proposed by Zhou in 2001 was determined to provide the best compromise for the current study. The simulated system was constructed with two layers of Cu and Mo forming an incoherent fcc-Cu(111)/bcc-Mo(110) interface, based on the Nishiyama–Wassermann (NW) and Kurdjumov–Sachs (KS) orientation relationships (OR). The interfacial energies were calculated for each orientation relationship. The NW configuration emerged as the most stable, with an interfacial energy of 1.83 J/m², compared to 1.97 J/m² for the KS orientation. Subsequent simulations were dedicated to modeling Cu atomic deposition onto a Mo(110) substrate at 300 K. These simulations resulted in the formation of a dense layer with only a few defects in the two Cu planes closest to the interface. The interfacial structures were characterized by computing selected area electron diffraction (SAED) patterns. A direct comparison of theoretical and numerical SAED patterns confirmed the presence of the NW orientation relationship in the nanocomposites formed during deposition, corroborating the results obtained with the model fcc-Cu(111)/bcc-Mo(110) interfaces.