Measurement of neutron birefringence in magnetic structures

Regularly arranged Bloch walls separating domains in which the angles between magnetization directions are 900 or (with an applied field) 56.20, allow the refraction to be measured in the case where only a magnetization component is reversed at the boundary. The results of very precise angle measurements are described by a simple continuum model of refraction, from a solution of the Schroedinger equation. This shows that the fundamental dependence of magnetic scattering on the magnetization component normal to the scattering vector, given by Halpern and Johnson, in this case does not give the correct description