Temperature Dependence of Short-Range Order in β-Brass

Critical scattering of neutrons around the superlattice reflections (1, 0, 0) and (1, 1, 1) from a single crystal of beta-brass has been measured at temperatures from 2 to 25deg C above the transition temperature. The temperature dependence of the critical peak intensity, proportional to the susceptibility chi, and that of the inverse correlation range k 1 were, respectively, fitted to the power laws chiprop((T-Tc)/T)-gamma and k 1 = (k/a)times((T-Tc)/Tc)nu, yielding gamma = 1.25plusmn0.02, nu = 0.65plusmn0.02, and k = 3.0plusmn0.3. Here a is the cube edge of the unit cell. These results agree with the theoretical predictions of the Ising model.