Non-specular reflectivity of spin flipped neutrons

Abstract

For the first time we observed large intensity non-specular reflection peaks of neutrons incident at small grazing angles on not fully magnetized ferromagnetic samples. In addition to the normal specular reflection spin flipped neutrons are reflected at distinctly higher (lower) angles if the incoming spin down (spin up) neutrons hit the surface at angles near the respective critical angle. The same effect occurs in transmission. The angles at which the non-specular reflection occurs can be calculated by a simple model, which assumes a spin flip without a change of direction and takes into account the different refraction angles of the original and the flipped spin state when the neutrons leave the sample.