MODIFIED ANALYTICAL EMBEDDED ATOM METHOD (MAEAM) INTERATOMIC POTENTIALS FOR BODY CENTRED CUBIC (BCC) TRANSITION METALS AND VACANCY MECHANISM

O. O. Popoola; F. Matthew–Ojelabi; G. S. Agunbiade; G. E. Adesakin; T.H. Akande

Volume : VI, Issue : IV, April - 2017

MODIFIED ANALYTICAL EMBEDDED ATOM METHOD (MAEAM) INTERATOMIC POTENTIALS FOR BODY CENTRED CUBIC (BCC) TRANSITION METALS AND VACANCY MECHANISM

O. O. Popoola, F. Matthew Ojelabi, G. S. Agunbiade, G. E. Adesakin, T. H. Akande

Abstract :

In this work, modified analytical embedded atom method, MAEAM was extended to the study of interatomic potentials for body centred cubic (bcc) transition metals. In MAEAM, the modification term is a function of parameterization for all bcc transition metals considered in this work. The modified term is developed to model the effect of angular dependence of the electron density, which manifests itself in directional bonding and bond–bending forces in the bcc crystals. The results obtained in this work for mono–vacancy formation, migration and activation energies were in good agreement with the experimental data, this tells us that the modified analytical embedded atom method is useful in the determination of interatomic potentials for body centred cubic transition metals. The mono–vacancy formation energy neither increases nor decreases as the lattice constant increases. The computed value of mono–vacancy migration energy is lower than the result of ab initio calculation. These could be due to the discrepancy in the modification term, fitting parameter and the contribution to the energy from many–body effects in the embedding function. The computed value of mono–vacancy activation energy is lower at most point compare to some other result of ab initio calculation.