Energy filtered Lorentz microscopy

Energy-filtered Lorentz microscopy (EFLM) combines a post-column energy filter with a high-resolution TEM, operated with the main objective lens switched off. In this paper we use a magnetostrictive material, Terfenol-D (Tb0.73Dy0.27Fe1.95), to illustrate the benefits of zero-loss filtering on both standard and coherent Fresnel and Foucault modes. It is shown that the signal-to-noise ratio of Foucault images is improved by an order of magnitude. We present a detailed study of magnetic domain configurations in the vicinity of growth twins and show that the magnetic resolution of the system is better than 5 nm. Our observations compare favorably with micromagnetic models. We also show that magnetic induction mapping becomes a viable technique in thicker regions when the inelastically scattered electrons have been removed from the images. Finally, we present simulations of Fresnel and Foucault images, assuming two-dimensional periodic boundary conditions for the computation of the Aharonov-Bohm phase shift.