Experiments on the Existence of Order in Ni–25%Co

Three kinds of experiments were conducted to determine whether and to what extent order exists in Ni–25%Co (‘Ni₃Co’). These were X-ray diffraction, both searching for superlattice lines using Co K_β radiation to maximize anomalous scattering, and lattice parameter measurements; electron microscopy, both diffraction and dislocation pair analysis; and mechanical properties. None of these showed any evidence of order, in agreement with previous experiments. It was concluded that order in Ni–25 %Co, if it exists, must be very slight.