Atomic Short‐Range Order in Cu17 at% Mn

The elastic diffuse neutron scattering from a Cu–17.2 at% Mn single crystal aged at 483 K to produce an equilibrium state of atomic short‐range order is measured at room temperature in a minimum separation volume of reciprocal space. Warren‐Cowley short‐range order parameters and coefficients of linear static displacement scattering are determined by least‐squares fitting. Effective pair potentials obtained from the short‐range order parameters by applying the inverse Monte‐Carlo method are used to calculate the diffuse antiphase boundary energy γAPB. For copper‐base alloys the concentration dependence of γAPB is one of the suggested reasons for the transition of wavy to planar slip. Based on the values of γAPB, the concentration ranges for the transition in CuMn, CuAl, and CuZn may be understood.