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3. Spatially resolved TiOx phases in RRAM conductive nanofilaments using soft X-ray spectromicroscopy

Author

Carta, Daniela, Hitchcock, Adam, Guttmann, Peter, Regoutz, Anna, Khiat, Ali, Serb, Alexantru, Gupta, Isha, and Prodromakis, Themistoklis

Subjects
Condensed Matter - Materials Science
Abstract

Reduction in metal-oxide thin films has been suggested as the key mechanism responsible for forming conductive nanofilaments within solid-state memory devices, enabling their resistive switching capacity. The quantitative spatial identification of such filaments is a daunting task, particularly for metal-oxides capable of exhibiting multiple phases as in the case of TiOx. Here, we spatially resolve and chemically characterize distinct TiOx phases in localized regions of a TiOx-based memristive device by combining full-field transmission X-ray microscopy with soft X-ray spectroscopic analysis that is performed on lamella samples. We particularly show that electrically pre-switched devices in low-resistive states comprise reduced disordered phases with O/Ti ratios close to Ti2O3 stoichiometry that aggregate in a ~ 100 nm filamentary region electrically conducting the top and bottom electrodes of the devices. We have also identified crystalline rutile and orthorhombic-like TiO2 phases in the region adjacent to the filament, suggesting that the temperature increases locally up to 1000 K, validating the role of Joule heating in resistive switching. Contrary to previous studies, our approach enables to simultaneously investigate morphological and chemical changes in a quantitative manner without incurring difficulties imposed by interpretation of electron diffraction patterns acquired via conventional electron microscopy techniques., Comment: 23 pages, 14 figures more...

Published
2015

10. Revealing the degradation pathways of layered Li-rich oxide cathodes

Author

He, Xin, primary, Liu, Zhimeng, additional, Zeng, Yuqiang, additional, Tan, Junyang, additional, Wang, Hailong, additional, Zhu, Yudong, additional, Geng, Xin, additional, Guttmann, Peter, additional, Hou, Xu, additional, Yang, Yang, additional, Xu, Yunkai, additional, Cloetens, Peter, additional, Wei, Yinping, additional, Lu, Jun, additional, Li, Jie, additional, Liu, Bilu, additional, Winter, Martin, additional, Kostecki, Robert, additional, and Lin, Yuanjing, additional more...

Published
2023
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13. Structural Basis of Vesicle Formation at the Inner Nuclear Membrane

Author

Hagen, Christoph, Dent, Kyle C., Zeev-Ben-Mordehai, Tzviya, Grange, Michael, Bosse, Jens B., Whittle, Cathy, Klupp, Barbara G., Siebert, C. Alistair, Vasishtan, Daven, Bäuerlein, Felix J.B., Cheleski, Juliana, Werner, Stephan, Guttmann, Peter, Rehbein, Stefan, Henzler, Katja, Demmerle, Justin, Adler, Barbara, Koszinowski, Ulrich, Schermelleh, Lothar, Schneider, Gerd, Enquist, Lynn W., Plitzko, Jürgen M., Mettenleiter, Thomas C., and Grünewald, Kay more...

Published
2015
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18. T Cells Kill Bacteria Captured by Transinfection from Dendritic Cells and Confer Protection in Mice

Author

Cruz-Adalia, Aránzazu, Ramirez-Santiago, Guillermo, Calabia-Linares, Carmen, Torres-Torresano, Mónica, Feo, Lidia, Galán-Díez, Marta, Fernández-Ruiz, Elena, Pereiro, Eva, Guttmann, Peter, Chiappi, Michele, Schneider, Gerd, Carrascosa, José López, Chichón, Francisco Javier, Martínez del Hoyo, Gloria, Sánchez-Madrid, Francisco, and Veiga, Esteban more...

Published
2014
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19. Spectromicroscopy of Nanoscale Materials in the Tender X‐Ray Regime Enabled by a High Efficient Multilayer‐Based Grating Monochromator

Author

Werner, Stephan, primary, Guttmann, Peter, additional, Siewert, Frank, additional, Sokolov, Andrey, additional, Mast, Matthias, additional, Huang, Qiushi, additional, Feng, Yufei, additional, Li, Tongzhou, additional, Senf, Friedmar, additional, Follath, Rolf, additional, Liao, Zhohngquan, additional, Kutukova, Kristina, additional, Zhang, Jian, additional, Feng, Xinliang, additional, Wang, Zhan‐Shan, additional, Zschech, Ehrenfried, additional, and Schneider, Gerd, additional more...

Published
2022
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29. Spectromicroscopy of Nanoscale Materials in the Tender X‐Ray Regime Enabled by a High Efficient Multilayer‐Based Grating Monochromator

Author

Werner, Stephan, Guttmann, Peter, Siewert, Frank, Sokolov, Andrey, Mast, Matthias, Huang, Qiushi, Feng, Yufei, Li, Tongzhou, Senf, Friedmar, Follath, Rolf, Liao, Zhohngquan, Kutukova, Kristina, Zhang, Jian, Feng, Xinliang, Wang, Zhan‐Shan, Zschech, Ehrenfried, Schneider, Gerd, Werner, Stephan, Guttmann, Peter, Siewert, Frank, Sokolov, Andrey, Mast, Matthias, Huang, Qiushi, Feng, Yufei, Li, Tongzhou, Senf, Friedmar, Follath, Rolf, Liao, Zhohngquan, Kutukova, Kristina, Zhang, Jian, Feng, Xinliang, Wang, Zhan‐Shan, Zschech, Ehrenfried, and Schneider, Gerd more...

Abstract

The combination of near edge X-ray absorption spectroscopy with nanoscale X-ray imaging is a powerful analytical tool for many applications in energy technologies, catalysis, which are critical to combat climate change, as well as microelectronics and life science. Materials from these scientific areas often contain key elements, such as Si, P, S, Y, Zr, Nb, and Mo as well as lanthanides, whose X-ray absorption edges lie in the so-called tender photon energy range 1.5–5.0 keV. Neither conventional grazing incidence grating nor crystal monochromators have high transmission in this energy range, thereby yielding the tender photon energy gap. To close this gap, a monochromator setup based on a multilayer coated blazed plane grating and plane mirror is devised. The measurements show that this novel concept improves the photon flux in the tender X-ray regime by two-orders-of-magnitude enabling previously unattainable laboratory and synchrotron-based studies. This setup is applied to perform nanoscale spectromicroscopy studies. The high photon flux provides sufficient sensitivity to obtain the electronic structure of Mo in platinum-free MoNi4 nanoparticles for electrochemical energy conversion. Additionally, it is shown that the chemical bonding of nano-structures in integrated circuits can be distinguished by the electronic configuration at the Si-K edge., Peer Reviewed more...

Published
2022

34. Spectromicroscopy of Nanoscale Materials in the Tender X‐Ray Regime Enabled by a High Efficient Multilayer‐Based Grating Monochromator.

Author

Werner, Stephan, Guttmann, Peter, Siewert, Frank, Sokolov, Andrey, Mast, Matthias, Huang, Qiushi, Feng, Yufei, Li, Tongzhou, Senf, Friedmar, Follath, Rolf, Liao, Zhohngquan, Kutukova, Kristina, Zhang, Jian, Feng, Xinliang, Wang, Zhan‐Shan, Zschech, Ehrenfried, and Schneider, Gerd more...

Subjects
*LIFE sciences, *MONOCHROMATORS, *NANOSTRUCTURED materials, *MIRRORS, *PHOTON flux, *X-rays, *FREE electron lasers
Abstract

The combination of near edge X‐ray absorption spectroscopy with nanoscale X‐ray imaging is a powerful analytical tool for many applications in energy technologies, catalysis, which are critical to combat climate change, as well as microelectronics and life science. Materials from these scientific areas often contain key elements, such as Si, P, S, Y, Zr, Nb, and Mo as well as lanthanides, whose X‐ray absorption edges lie in the so‐called tender photon energy range 1.5–5.0 keV. Neither conventional grazing incidence grating nor crystal monochromators have high transmission in this energy range, thereby yielding the tender photon energy gap. To close this gap, a monochromator setup based on a multilayer coated blazed plane grating and plane mirror is devised. The measurements show that this novel concept improves the photon flux in the tender X‐ray regime by two‐orders‐of‐magnitude enabling previously unattainable laboratory and synchrotron‐based studies. This setup is applied to perform nanoscale spectromicroscopy studies. The high photon flux provides sufficient sensitivity to obtain the electronic structure of Mo in platinum‐free MoNi4 nanoparticles for electrochemical energy conversion. Additionally, it is shown that the chemical bonding of nano‐structures in integrated circuits can be distinguished by the electronic configuration at the Si‐K edge. [ABSTRACT FROM AUTHOR] more...

Published
2023
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35. Probing the Intracellular Bio-Nano Interface in Different Cell Lines with Gold Nanostars

Author

Spedalieri, Cecilia, Szekeres, Gergo Péter, Werner, Stephan, Guttmann, Peter, and Kneipp, Janina

Subjects
SERS, nanotomography, HCT-116, J774, 570 Biologie, 3T3, Article, nanoparticle uptake, Chemistry, 540 Chemie und zugeordnete Wissenschaften, protein corona, ddc:570, ddc:540, endocytosis, gold nanostars, QD1-999
Abstract

Gold nanostars are a versatile plasmonic nanomaterial with many applications in bioanalysis. Their interactions with animal cells of three different cell lines are studied here at the molecular and ultrastructural level at an early stage of endolysosomal processing. Using the gold nanostars themselves as substrate for surface-enhanced Raman scattering, their protein corona and the molecules in the endolysosomal environment were characterized. Localization, morphology, and size of the nanostar aggregates in the endolysosomal compartment of the cells were probed by cryo soft-X-ray nanotomography. The processing of the nanostars by macrophages of cell line J774 differed greatly from that in the fibroblast cell line 3T3 and in the epithelial cell line HCT-116, and the structure and composition of the biomolecular corona was found to resemble that of spherical gold nanoparticles in the same cells. Data obtained with gold nanostars of varied morphology indicate that the biomolecular interactions at the surface in vivo are influenced by the spike length, with increased interaction with hydrophobic groups of proteins and lipids for longer spike lengths, and independent of the cell line. The results will support optimized nanostar synthesis and delivery for sensing, imaging, and theranostics. Deutsche Forschungsgemeinschaft FP7 Ideas: European Research Council more...

Published
2021

38. Soft X-ray to characterize polyelectrolyte assemblies

Author

Kohler, Karen, Dejugnat, Christophe, Dubois, Monique, Zemb, Thomas, Sukhorukov, Gleb B., Guttmann, Peter, and Mohwald, Helmuth

Subjects
Colloids -- Chemical properties, Polyelectrolytes -- Chemical properties, Chemicals, plastics and rubber industries
Abstract

Transmission microscopy with soft X-rays (TXM) is used for imaging in-situ polyelectrolyte assemblies in aqueous environment. The method is found to be element specific, exhibiting a lateral resolution of 20 nm, and is coming up as a highly promising approach in colloid and polyelectrolyte science. more...

Published
2007

43. Cover Image

Author

Hempel, Casper, primary, Kapishnikov, Sergey, additional, Perez‐Berna, Ana Joaquina, additional, Werner, Stephan, additional, Guttmann, Peter, additional, Pereiro, Eva, additional, Qvortrup, Klaus, additional, and Andresen, Thomas Lars, additional more...

Published
2020
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46. Röntgenmikroskopie

Author

Schmahl, Günter, Rudolph, Dietbert, Niemann, Bastian, Guttmann, Peter, Thieme, Jürgen, and Schneider, Gerd

Published
1996
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47. The need to freeze—Dehydration during specimen preparation for electron microscopy collapses the endothelial glycocalyx regardless of fixation method

Author

Hempel, Casper, Kapishnikov, Sergey, Perez-Berna, Ana Joaquina, Werner, Stephan, Guttmann, Peter, Pereiro, Eva, Qvortrup, Klaus, Andresen, Thomas Lars, Hempel, Casper, Kapishnikov, Sergey, Perez-Berna, Ana Joaquina, Werner, Stephan, Guttmann, Peter, Pereiro, Eva, Qvortrup, Klaus, and Andresen, Thomas Lars more...

Abstract

Objective: The endothelial glycocalyx covers the luminal surface of the endothelium and plays key roles in vascular function. Despite its biological importance, ideal visualization techniques are lacking. The current study aimed to improve the preservation and subsequent imaging quality of the endothelial glycocalyx. Methods: In mice, the endothelial glycocalyx was contrasted with a mixture of lanthanum and dysprosium (LaDy). Standard chemical fixation was compared with high-pressure frozen specimens processed with freeze substitution. Also, isolated brain microvessels and cultured endothelial cells were high-pressure frozen and by transmission soft x-rays, imaged under cryogenic conditions. Results: The endothelial glycocalyx was in some tissues significantly more voluminous from chemically fixed specimens compared with high-pressure frozen specimens. LaDy labeling introduced excessive absorption contrast, which impeded glycocalyx measurements in isolated brain microvessels when using transmission soft x-rays. In non-contrasted vessels, the glycocalyx was not resolved. LaDy-contrasted, cultured brain endothelial cells allowed to assess glycocalyx volume in vitro. Conclusions: Both chemical and cryogenic fixation followed by dehydration lead to substantial collapse of the glycocalyx. Cryogenic fixation without freeze substitution could be a way forward although transmission soft x-ray tomography based solely on amplitude contrast seems unsuitable. more...

Published
2020

48. Biomolecular environment, quantification, and intracellular interaction of multifunctional magnetic SERS nanoprobes† †Electronic supplementary information (ESI) available. See DOI: 10.1039/c6an00890a

Author

Büchner, Tina, Drescher, Daniela, Merk, Virginia, Traub, Heike, Guttmann, Peter, Werner, Stephan, Jakubowski, Norbert, Schneider, Gerd, and Kneipp, Janina

Subjects
Chemistry
Abstract

Multifunctional composite nanoprobes, Ag–Magnetite and Au–Magnetite, were manipulated in fibroblast cells and characterized using SERS, LA-ICP-MS, and nanotomography., Multifunctional composite nanoprobes consisting of iron oxide nanoparticles linked to silver and gold nanoparticles, Ag–Magnetite and Au–Magnetite, respectively, were introduced by endocytic uptake into cultured fibroblast cells. The cells containing the non-toxic nanoprobes were shown to be displaceable in an external magnetic field and can be manipulated in microfluidic channels. The distribution of the composite nanostructures that are contained in the endosomal system is discussed on the basis of surface-enhanced Raman scattering (SERS) mapping, quantitative laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) micromapping, and cryo soft X-ray tomography (cryo soft-XRT). Cryo soft-XRT of intact, vitrified cells reveals that the composite nanoprobes form intra-endosomal aggregates. The nanoprobes provide SERS signals from the biomolecular composition of their surface in the endosomal environment. The SERS data indicate the high stability of the nanoprobes and of their plasmonic properties in the harsh environment of endosomes and lysosomes. The spectra point at the molecular composition at the surface of the Ag–Magnetite and Au–Magnetite nanostructures that is very similar to that of other composite structures, but different from the composition of pure silver and gold SERS nanoprobes used for intracellular investigations. As shown by the LA-ICP-MS data, the uptake efficiency of the magnetite composites is approximately two to three times higher than that of the pure gold and silver nanoparticles. more...

Published
2016

50. Cells Undergo Major Changes in the Quantity of Cytoplasmic Organelles after Uptake of Gold Nanoparticles with Biologically Relevant Surface Coatings

Author

Kepsutlu, Burcu, primary, Wycisk, Virginia, additional, Achazi, Katharina, additional, Kapishnikov, Sergey, additional, Pérez-Berná, Ana Joaquina, additional, Guttmann, Peter, additional, Cossmer, Antje, additional, Pereiro, Eva, additional, Ewers, Helge, additional, Ballauff, Matthias, additional, Schneider, Gerd, additional, and McNally, James G., additional more...

Published
2020
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