The evolution of the antiferromagnetic phase across the temperature-driven ferromagnetic (FM) to antiferromagnetic (AF) phase transition in epitaxial FeRh thin films was studied by x-ray magnetic linear and circular dichroism (XMLD and XMCD) and photoemission electron microscopy. By comparing XMLD and XMCD images recorded at the same temperature, the AF phase was identified, its structure directly imaged, and its evolution studied across the transition. A quantitative analysis of the correlation length of the images shows differences between the characteristic length scale of the two phases with the AF phase having a finer feature size. The asymmetry of the transition from FM to AF upon cooling and AF-FM upon heating is evidenced: upon cooling the formation of AF phase is dominated by nucleation at defects, with little subsequent growth, resulting in a small and non-random final AF domain structure, while upon heating, heterogeneous nucleation at different sites followed by significant domain size growth of the FM phase is observed, resulting in a non-reproducible final FM large domain structure.

The overall goal of our work is to disrupt pervasive narratives and misplaced assessments of what defines scientific brilliance, specifically in the introductory chemistry classroom. The traditional design of science, technology, education, and math (STEM) courses perpetuates the narrow view that intelligence is characterized by innate talent, knowing lots of information, and being quick and correct. This view disproportionately impacts students historically underserved in STEM. The Chem Avengers aim to transform chemistry education into an inclusive practice where all learners can thrive. The work reported here is focused on creating and implementing group-worthy tasks that support equitable participation. These tasks center around sorting, using, and making sense of data, trends, and patterns.

A fabrication process has been developed for high energy ion beam assisted deposition (IBAD) biaxial texturing of ultrathin (∼1 nm) MgO films, using a high ion-to-atom ratio and post-deposition annealing instead of a homoepitaxial MgO layer. These films serve as the seed layer for epitaxial growth of materials on amorphous substrates such as electron/X-ray transparent membranes or nanocalorimetry devices. Stress measurements and atomic force microscopy of the MgO films reveal decreased stress and surface roughness, while X-ray diffraction of epitaxial overlayers demonstrates the improved crystal quality of films grown epitaxially on IBAD MgO. The process simplifies the synthesis of IBAD MgO, fundamentally solves the “wrinkle” issue induced by the homoepitaxial layer on sub-50 nm membranes, and enables studies of epitaxial materials in electron/X-ray transmission and nanocalorimetry.

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