Contribution of stacking fault in lowering the theoretical density of nickel

Abstract

It has been shown with the help of first-principle based calculations that the occurrence of stacking fault (SF) changes the density of nickel. Calculations, based upon a twelve {111}-plane supercell of face-centered-cubic (fcc) nickel show that the stacking fault energy in the case of "conventional'' stacking is higher by similar to 2 mJ/m(2) than that of the supercell having an appropriate dilation along the fault-plane normal. The {111}-type stacking fault energy of fcc-Ni, 136.683 mJ/m(2), has been calculated using 4.09746 x 10(5) mm(2)/mm(3) SF density, which has resulted in the decrease in the bulk density of fcc-Ni by 0.0895%. This approach of relaxation of a structure with stacking faults along the plane normal may be extended to calculate more accurate generalized stacking fault and to measure the lattice distortion due to various values of defect-densities. (C) 2013 Elsevier B.V. All rights reserved.