First-principles studies on bonding mechanism at Ni/X bimetallic interfaces (X=Ta, W, Re and Ru)

The atomic structures and bonding mechanism of Ni/X [X=Ta(110), W(110), Re(0001) and Ru(0001)] bimetallic surfaces have been studied using the local-density full-potential linearized augmented plane-wave (FLAPW) method with the atomic force approach. The strength of the overlayer–substrate bonding decreases in the sequence Ta>W>Re>Ru, which agrees with the thermal desorption mass spectroscopy results of Rodriguez et al. Charge polarization induced in the nickel layer by the substrate plays the key role in determining or altering the electronic and chemical properties of the nickel overlayer and the bonding of the bimetallic systems.