STRUCTURE AND DYNAMICS OF AN AG OVERLAYER ON NI(100) - COMPARISON OF EMBEDDED ATOM AND PAIR POTENTIAL RESULTS

We present a comparison of the results obtained from molecular dynamics simulations of an overlayer of Ag on Ni(100) using potentials from the embedded atom method, on the one hand, and central, pair-wise potentials, on the other. At room temperature there is qualitative agreement between the most striking result obtained from the two types of potential, namely that the Ag atoms slide back and forth over the Ni substrate, maintaining an average distance above the nickel of 2.15 angstrom. The mean square vibrational amplitudes of the atoms exhibit interesting similarities and differences at 300 K. At 1200 K there emerge also qualitative differences in the predictions from the two methods, alluding to appearance of anharmonic effects.