Extended reciprocal space observation of artificial spin ice with x-ray resonant magnetic scattering

Abstract

Soft x-ray resonant magnetic scattering is an element-sensitive technique that enables the characterization of the magnetic properties of a wide variety of systems. Here we apply this technique to study lithographically produced artificial spin ice, a particular class of magnetically frustrated systems comprising arrays of nanomagnets. Using a CCD detector we can access a large fraction of the reciprocal space at once, allowing us to easily distinguish the signatures of the magnetic ground-state ordering. Comparing the dichroic signal at the position of the Bragg peaks with model calculations based on the kinematical theory of x-ray diffraction, we are able to determine the number of reversed moments as a function of applied magnetic field for each of the two sublattices. This study demonstrates the benefit of having direct access to a significant fraction of the reciprocal space, and opens the way towards more sophisticated x-ray based experiments on artificial spin ice such as scattering of coherent x-ray beams to explore the dynamics of thermally activated systems.