Fault energies in ordered and disordered Cu₃Au

Abstract

Partial dislocations in ordered and disordered Cu₃Au were imaged using the weak-beam method of electron microscopy. The stacking fault energies (γ) of ordered and disordered Cu₃Au and the antiphase boundary (APB) energy on {111} planes of ordered Cu₃Au were determined from the measured spacings of extended dislocation configurations. It is found that γ ordered Cu₃Au < γ disordered Cu₃Au in agreement with the results of measurements of stacking fault probability. The experimental value of APB energy in fully ordered Cu₃Au (39±5 erg cm⁻²) is compared with theoretical estimates.