The temperature and frequency dependence of the inelastic neutron scattering from an Ising magnet

Abstract

The magnetic inelastic scattering of neutrons from a spin-[Formula: see text] Ising system is considered. For the two-dimensional plane square lattice, the exact energy distribution of the scattering is obtained at all temperatures. It consists of a number of discrete levels, the envelope of which varies most markedly in the critical region. Some qualitative projections are also made concerning three-dimensional systems. For both two- and three-dimensional Ising models there can be no wave-vector dependence of the inelastic scattering function because there is correlation only between z components of the spins on different sites.