Accurate Interatomic Potentials for Ni, Al and Ni3Al

To obtain meaningful results from atomistic simulations of materials, the interatomic potentials must be capable of reproducing the thermodynamic properties of the system of interest. Pairwise potentials have known deficiencies that make them unsuitable for quantitative investigations of defective regions such as crack tips and free surfaces. Daw and Baskes [Phys. Rev. B 29, 6443 (1984)] have shown that including a local “volume” term for each atom gives the necessary many-body character without the severe computational dependence of explicit n-body potential terms. Using a similar approach, we have fit an interatomic potential to the Ni 3 Al alloy system. This potential can treat diatomic Ni 2 , diatomic Al 2 , fcc Ni, fcc Al and L1 2 Ni 3 Al on an equal footing. Details of the fitting procedure are presented, along with the calculation of some properties not included in the fit.

[1]  John A. Nelder,et al.  A Simplex Method for Function Minimization , 1965, Comput. J..

[2]  G. Herzberg,et al.  Constants of diatomic molecules , 1979 .

[3]  Herbert F. Wang,et al.  Single Crystal Elastic Constants and Calculated Aggregate Properties. A Handbook , 1971 .

[4]  Z. Y. Chen,et al.  Thermal vacancies in (Ni, Co)Ga , 1986 .

[5]  L. Murr.  Interfacial phenomena in metals and alloys , 1975 .

[6]  P. Veyssiére,et al.  On the presence of super lattice intrinsic stacking faults in plastically deformed Ni3Al , 1985 .

[7]  C. Kittel.  Introduction to solid state physics , 1954 .

[8]  Foiles,et al.  Calculation of the surface segregation of Ni-Cu alloys with the use of the embedded-atom method. , 1985, Physical review. B, Condensed matter.

[9]  Defect Clusters in B.C.C. Metals,et al.  Point defects and defect interactions in metals , 1982 .

[10]  M. Doyama,et al.  Study of vacancies in the intermetallic compound Ni3Al by positron annihilation , 1984 .

[11]  Chen,et al.  Structure and fractal dimension of protein-detergent complexes. , 1986, Physical review letters.

[12]  R. C. Weast.  Handbook of chemistry and physics , 1973 .

[13]  Joshua R. Smith,et al.  Universal features of the equation of state of metals , 1984 .

[14]  B. N. Brockhouse,et al.  Pseudopotentials in the theory of metals , 1966 .

[15]  M. Baskes,et al.  Embedded-atom method: Derivation and application to impurities, surfaces, and other defects in metals , 1984 .

[16]  D. T. Hawkins,et al.  Selected values of the thermodynamic properties of binary alloys , 1973 .

[17]  Foiles,et al.  Embedded-atom-method functions for the fcc metals Cu, Ag, Au, Ni, Pd, Pt, and their alloys. , 1986, Physical review. B, Condensed matter.