The temperature dependence of long-range order langPrang has been determined from the temperature variation of a superlattice Bragg reflection. The results fitted a power law langPrang prop (Tc-T)beta with Tc the critical temperature and beta = 0.305plusmn0.005, in agreement with the theoretical prediction 0.303 <beta <0.318 obtained from a comparison of the measured line profiles of the (1, 0, 0) superlattice reflection at 15.5 and 2.2deg below Tc. The ratio between the susceptibilities chi+(DeltaT) and chi-(DeltaT) DeltaT deg below and above Tc was found to be 5.5plusmn2.0 at DeltaT = 4.4deg and 8.5plusmn3.0 at DeltaT = 2.1deg. The Ising-model theory predicts the ratio to be 5.2 independent of DeltaT.
Als-Nielsen, J. A., & Dietrich, O. W. (1967). Long-Range Order and Critical Scattering of Neutrons below the Transition Temperature in β-Brass. PHYSICAL REVIEW, 153(3), 717-721. https://doi.org/10.1103/PhysRev.153.717