Pair-Correlation Function in Disorderedβ-Brass as Studied by Neutron Diffraction

Critical neutron scattering around a superlattice reflection above $T_c$ yields information on the pair correlation function for occupation of lattice sites. The Ornstein-Zernike correlation function $\frac{e^{-{\kappa }_{1}r}}{r}$ is proved to fit the data excellently, and at 8.9°K above $T_c$ the inverse correlation range ${\kappa }_1$ is found to be 0.0615 ${\mathrm{\AA }}^{-1\mathrm{}}$ with an estimated uncertainty of ±2%. Correction for instrumental resolution is an essential part of the interpretation of the data and is described in detail.