Speaker
Description
INTRODUCTION
Synchrotron-based full-field soft X-ray transmission microscopy (TXM) provides ~30 nm spatial resolution combined with tunable photon energy, enabling chemical mapping via pixel-resolved X-ray absorption spectra. This technique allows the identification and quantification of chemical species independently of their crystalline state. When the absorption edge of interest lies within the “water window” energy range, TXM additionally enables high-contrast, energy-dependent native imaging of fully hydrated, cryopreserved samples. Furthermore, the two-dimensional chemical information obtained by TXM can be extended into three dimensions by performing tomography on the same field of view. The combination of intermediate spatial resolution, penetration depth, and chemical sensitivity makes TXM an ideal complementary tool in correlative and multi-technique workflows.
METHODS
These capabilities are illustrated through selected examples from recent materials and biological science experiments carried out at the Mistral beamline of the ALBA Synchrotron [1], one of the world’s leading full-field soft X-ray transmission microscopy beamlines.
RESULTS AND DISCUSSION
In [2], cryo-TXM at the N K-edge was crucial for ruling out a continuous transformation of melanosomes (melanin-rich organelles) into guanine crystal-containing organelles in zebrafish dorsal fin cells, complementing previous observations obtained by cryo-electron imaging techniques. In [3], TXM was applied to α-MnO₂ cathodes of rechargeable aqueous Zn–MnO₂ batteries at different states of charge. Imaging at the Mn L-edge enabled the visualization of Mn(III)-rich regions at the nanowire borders, providing enhanced sensitivity to local oxidation state. Combined with operando hard X-ray absorption spectroscopy and electron microscopy, these observations refined the understanding of the electrochemical mechanisms governing this complex battery system.
CONCLUSION
These applications demonstrate that TXM provides unique capabilities, bridging critical gaps in spatial resolution, penetration depth, and chemical sensitivity among other imaging and spectroscopic techniques.
[1] Sorrentino, A., et al., ‘MISTRAL: a transmission soft X-ray microscopy beamline for cryo nano-tomography of biological samples and magnetic domains imaging’. J. Synchrotron Rad. (2015), 22, 1112-1117. DOI: 10.1107/S1600577515008632
[2] ‘De novo organelle biogenesis and metabolic rewiring drive direct cellular transdifferentiation’, Yael Noy et. al. PNAS submitted.
[3] Liu, C., et al. ‘Unveiling Capacity Limitations of MnO2 in Rechargeable Zn Chemistry’. Energy Environ. Sci., (2025),18, 9611-9622. DOI: 10.1039/D5EE03588K