Small-Angle Scattering of Neutrons by FeCl₂ near the Néel Temperature

Abstract

Small-angle scattering cross-section for slow neutrons by FeCl₂ above but near the Néel temperature is calculated with a method which is an extension of Zernike’s theory of propagation of order. The result is compared with the experimental data and a reasonable agreement is found if the ratio of the two exchange coupling constants in this crystal is assumed to be about 0.08.