Short-range order in Ni₃Fe

Short-range order parameters were obtained for a single crystal of ⁶²Ni₃Fe quenched from above T_c. These are the first absolute measurements of diffuse elastic neutron scattering complete enough to separate the effects of local order and atomic displacements (up to quadratic terms) and indicate that neutrons are ideally suited for such studies. The results are compared to those obtained with X-rays. The short-range order intensity of Ni₃Fe is similar in shape to that for Cu₃Au but in this alloy it is due to the plate-like nature of ordered domains, not the antiphase domain boundaries which are present in such regions in Cu₃Au.