INVESTIGATION OF SCALING LAWS BY CRITICAL NEUTRON SCATTERING FROM BETA-BRASS

Using a Cu65-Zn β-brass crystal, the critical scattering of neutrons has been studied, both above and below Tc. The staggered susceptibilities χ vary as C+(TTc-1)-γ and C-(1-TTc)-γ′, respectively. We find that γ=γ′ within an accuracy of 3%, in agreement with the scaling hypothesis of static critical phenomena; and that C+C-=5.46±0.05, in excellent agreement with the recent parametric representation theory of Schofield and in fair agreement with the results of series expansions by Essam and Hunter. For fixed q, a flat maximum is observed in the wave-vector-dependent susceptibility χ(q,T) at temperatures which agree well with the predictions of Fisher and Burford. © 1969 The American Physical Society.