Calculation of the γ/γ′ interface free energy in the Ni-Al system by the capillary fluctuation method

Monte Carlo computer simulations with an embedded-atom potential are applied to study coherent γ/γ′ interfaces in the Ni-Al system. The (1 0 0) interface free energy has been extracted from the power spectrum of equilibrium shape fluctuations (capillary waves) and found to decrease with temperature from about 20 mJ m−2 at 550 K to about 10 mJ m−2 at 1200 K. These numbers are in reasonable agreement with existing experimental data. Strengths and weaknesses of the capillary wave method are discussed.