Agradecimentos: Diamond Light Source provided access to the I08-1 Soft X-ray Ptychography Facility with experiment Grants No. MG28255-1, No. MG32635-1, No. MG32984-2, and No. MG33254-1. J. N., M. D. P. M., L. T., and C. D. acknowledge funding from the Max Planck Society Lise Meitner Excellence Program and funding from the European Research Council (ERC) under the ERC Starting Grant No. 3DNANOQUANT 101116043. J. N. acknowledges support from the International Max Planck Research School for Chemistry and Physics of Quantum Materials. A. S., D. A. M., and G. B. thank Engineering and Physical Sciences Research Council United Kingdom for funding through Grants No. EP/T005963/1 and No. EP/N032128/1. This project has received funding from the European Union’s Horizon 2020 research and innovation program under Grant Agreement No. 101005611. R. H. acknowledges funding by the Electron and X-ray microscopy Community for structural and chemical Imaging Techniques for Earth materials (EXCITE) (Award No. G106564). The authors thank Po-Yen Tung and Simone Finizio for fruitful discussions. Z. P., E. R., and R. H. acknowledge Thermo Fisher Scientific for providing access to and supporting the cryo-EM facilities at the Cambridge Pharmaceutical Consortium Ver menos

Abstract: Imaging of nanoscale magnetic textures within extended material systems is of critical importance to both fundamental research and technological applications. While high-resolution magnetic imaging of thin nanoscale samples is well established with electron and soft x-ray microscopy, the extension to micrometer-thick systems currently requires hard x rays, which limits high-resolution imaging to rareearth magnets. Here, we overcome this limitation by establishing soft x-ray magnetic imaging of micrometer-thick systems using the pre-edge phase x-ray magnetic circular dichroism signal, thus making possible the study of a wide range of magnetic materials. By performing dichroic spectroptychography, we demonstrate high spatial resolution imaging of magnetic samples up to 1.7 mu m thick, an order of magnitude higher than conventionally possible with soft x-ray absorption-based techniques. We demonstrate the applicability of the technique by harnessing the pre-edge phase to image thick chiral helimagnets, and naturally occurring magnetite particles, gaining insight into their three-dimensional magnetic configuration. This new regime of magnetic imaging makes possible the study of extended non- rare-earth systems that have until now been inaccessible, including magnetic textures for future spintronic applications, non-rare-earth permanent magnets for energy harvesting, and the magnetic configuration of giant magnetofossils Ver menos