Neutron scattering study of the random field Ising film Fe0.5Zn0.5F2

Abstract The extinction-free neutron scattering for a 3.4 μm epitaxial film of the dilute antiferromagnet Fe 0.5 Zn 0.5 F 2 has been studied near the (100) magnetic Bragg point. For the H = 0 Bragg scattering we observe the random-exchange Ising model behavior I ≈ | t | 2 β with β = 0.35. For 0 H T has the opposite curvature from the H = 0 case near T c ( H ).