Reliable phase quantification in focused probe electron ptychography of thin materials
Ultramicroscopy. 2023 Aug 18;254:113829. doi: 10.1016/j.ultramic.2023.113829. Online ahead of print.ABSTRACTElectron ptychography provides highly sensitive, dose efficient phase images which can be corrected for aberrations after the data has been acquired. This is crucial when very precise quantification is required, such as with sensitivity to charge transfer due to bonding. Drift can now be essentially eliminated as a major impediment to focused probe ptychography, which benefits from the availability of easily interpretable simultaneous Z-contrast imaging. However challenges have remained when quantifying the ptychogra...
Source: Ultramicroscopy - August 26, 2023 Category: Laboratory Medicine Authors: Christoph Hofer Timothy J Pennycook Source Type: research
Convexity constraints on linear background models for electron energy-loss spectra
Ultramicroscopy. 2023 Aug 14;254:113830. doi: 10.1016/j.ultramic.2023.113830. Online ahead of print.ABSTRACTIn this paper convexity constraints are derived for a background model of electron energy loss spectra (EELS) that is linear in the fitting parameters. The model outperforms a power-law both on experimental and simulated backgrounds, especially for wide energy ranges, and thus improves elemental quantification results. Owing to the model's linearity, the constraints can be imposed through fitting by quadratic programming. This has important advantages over conventional nonlinear power-law fitting such as high speed a...
Source: Ultramicroscopy - August 26, 2023 Category: Laboratory Medicine Authors: Wouter Van den Broek Daen Jannis Jo Verbeeck Source Type: research
Reliable phase quantification in focused probe electron ptychography of thin materials
Ultramicroscopy. 2023 Aug 18;254:113829. doi: 10.1016/j.ultramic.2023.113829. Online ahead of print.ABSTRACTElectron ptychography provides highly sensitive, dose efficient phase images which can be corrected for aberrations after the data has been acquired. This is crucial when very precise quantification is required, such as with sensitivity to charge transfer due to bonding. Drift can now be essentially eliminated as a major impediment to focused probe ptychography, which benefits from the availability of easily interpretable simultaneous Z-contrast imaging. However challenges have remained when quantifying the ptychogra...
Source: Ultramicroscopy - August 26, 2023 Category: Laboratory Medicine Authors: Christoph Hofer Timothy J Pennycook Source Type: research
Convexity constraints on linear background models for electron energy-loss spectra
Ultramicroscopy. 2023 Aug 14;254:113830. doi: 10.1016/j.ultramic.2023.113830. Online ahead of print.ABSTRACTIn this paper convexity constraints are derived for a background model of electron energy loss spectra (EELS) that is linear in the fitting parameters. The model outperforms a power-law both on experimental and simulated backgrounds, especially for wide energy ranges, and thus improves elemental quantification results. Owing to the model's linearity, the constraints can be imposed through fitting by quadratic programming. This has important advantages over conventional nonlinear power-law fitting such as high speed a...
Source: Ultramicroscopy - August 26, 2023 Category: Laboratory Medicine Authors: Wouter Van den Broek Daen Jannis Jo Verbeeck Source Type: research
Reliable phase quantification in focused probe electron ptychography of thin materials
Ultramicroscopy. 2023 Aug 18;254:113829. doi: 10.1016/j.ultramic.2023.113829. Online ahead of print.ABSTRACTElectron ptychography provides highly sensitive, dose efficient phase images which can be corrected for aberrations after the data has been acquired. This is crucial when very precise quantification is required, such as with sensitivity to charge transfer due to bonding. Drift can now be essentially eliminated as a major impediment to focused probe ptychography, which benefits from the availability of easily interpretable simultaneous Z-contrast imaging. However challenges have remained when quantifying the ptychogra...
Source: Ultramicroscopy - August 26, 2023 Category: Laboratory Medicine Authors: Christoph Hofer Timothy J Pennycook Source Type: research
Convexity constraints on linear background models for electron energy-loss spectra
Ultramicroscopy. 2023 Aug 14;254:113830. doi: 10.1016/j.ultramic.2023.113830. Online ahead of print.ABSTRACTIn this paper convexity constraints are derived for a background model of electron energy loss spectra (EELS) that is linear in the fitting parameters. The model outperforms a power-law both on experimental and simulated backgrounds, especially for wide energy ranges, and thus improves elemental quantification results. Owing to the model's linearity, the constraints can be imposed through fitting by quadratic programming. This has important advantages over conventional nonlinear power-law fitting such as high speed a...
Source: Ultramicroscopy - August 26, 2023 Category: Laboratory Medicine Authors: Wouter Van den Broek Daen Jannis Jo Verbeeck Source Type: research
Morphology measurements by AFM tapping without causing surface damage: A phase shift characterization
Ultramicroscopy. 2023 Aug 18;254:113832. doi: 10.1016/j.ultramic.2023.113832. Online ahead of print.ABSTRACTThe morphology measurement of a surface can be done by using an atomic force microscope (AFM). However, it is difficult to ensure that the measurement does not introduce any damage to the sample surface. This paper proposes that phase shift, the phase change between the original surface and scanned area, can provide a characteristic signal of the tip-surface interaction. On a poly (methyl methacrylate) thin film, the present investigation explored the relationship between phase shift and nondestructive surface morpho...
Source: Ultramicroscopy - August 24, 2023 Category: Laboratory Medicine Authors: Yang He Yongda Yan Yanquan Geng Source Type: research
Morphology measurements by AFM tapping without causing surface damage: A phase shift characterization
Ultramicroscopy. 2023 Aug 18;254:113832. doi: 10.1016/j.ultramic.2023.113832. Online ahead of print.ABSTRACTThe morphology measurement of a surface can be done by using an atomic force microscope (AFM). However, it is difficult to ensure that the measurement does not introduce any damage to the sample surface. This paper proposes that phase shift, the phase change between the original surface and scanned area, can provide a characteristic signal of the tip-surface interaction. On a poly (methyl methacrylate) thin film, the present investigation explored the relationship between phase shift and nondestructive surface morpho...
Source: Ultramicroscopy - August 24, 2023 Category: Laboratory Medicine Authors: Yang He Yongda Yan Yanquan Geng Source Type: research
Morphology measurements by AFM tapping without causing surface damage: A phase shift characterization
Ultramicroscopy. 2023 Aug 18;254:113832. doi: 10.1016/j.ultramic.2023.113832. Online ahead of print.ABSTRACTThe morphology measurement of a surface can be done by using an atomic force microscope (AFM). However, it is difficult to ensure that the measurement does not introduce any damage to the sample surface. This paper proposes that phase shift, the phase change between the original surface and scanned area, can provide a characteristic signal of the tip-surface interaction. On a poly (methyl methacrylate) thin film, the present investigation explored the relationship between phase shift and nondestructive surface morpho...
Source: Ultramicroscopy - August 24, 2023 Category: Laboratory Medicine Authors: Yang He Yongda Yan Yanquan Geng Source Type: research
Chemistry and microstructure of C-supported Ru catalyst nanoparticles: A correlative study
Ultramicroscopy. 2023 Aug 11;254:113831. doi: 10.1016/j.ultramic.2023.113831. Online ahead of print.ABSTRACTRu@Pt core shell nanoparticles possess optimal catalytic properties that facilitate the anodic oxidation reaction of H2 with decreased Pt loading in hydrogen fuel cells. Moreover, since they preferentially oxidize CO, Pt poisoning is considerably reduced, which significantly improves the stability of the cell. The Ru cores used in this system are usually synthesized by dissolving a RuCl3*H2O precursor in an ethylene glycol-carbon black-NaOH mixture. However, the possibility that remnant Cl and Na from the synthesis p...
Source: Ultramicroscopy - August 19, 2023 Category: Laboratory Medicine Authors: Nicol ás A Rivas Rivas Alba Garz ón Manjón Miquel Vega-Paredes Se-Ho Kim Baptiste Gault Hosun Jun Chanwon Jung Viktoriya Berova Katharina Hengge Tilman Jurzinsky Christina Scheu Source Type: research
Chemistry and microstructure of C-supported Ru catalyst nanoparticles: A correlative study
Ultramicroscopy. 2023 Aug 11;254:113831. doi: 10.1016/j.ultramic.2023.113831. Online ahead of print.ABSTRACTRu@Pt core shell nanoparticles possess optimal catalytic properties that facilitate the anodic oxidation reaction of H2 with decreased Pt loading in hydrogen fuel cells. Moreover, since they preferentially oxidize CO, Pt poisoning is considerably reduced, which significantly improves the stability of the cell. The Ru cores used in this system are usually synthesized by dissolving a RuCl3*H2O precursor in an ethylene glycol-carbon black-NaOH mixture. However, the possibility that remnant Cl and Na from the synthesis p...
Source: Ultramicroscopy - August 19, 2023 Category: Laboratory Medicine Authors: Nicol ás A Rivas Rivas Alba Garz ón Manjón Miquel Vega-Paredes Se-Ho Kim Baptiste Gault Hosun Jun Chanwon Jung Viktoriya Berova Katharina Hengge Tilman Jurzinsky Christina Scheu Source Type: research
Chemistry and microstructure of C-supported Ru catalyst nanoparticles: A correlative study
Ultramicroscopy. 2023 Aug 11;254:113831. doi: 10.1016/j.ultramic.2023.113831. Online ahead of print.ABSTRACTRu@Pt core shell nanoparticles possess optimal catalytic properties that facilitate the anodic oxidation reaction of H2 with decreased Pt loading in hydrogen fuel cells. Moreover, since they preferentially oxidize CO, Pt poisoning is considerably reduced, which significantly improves the stability of the cell. The Ru cores used in this system are usually synthesized by dissolving a RuCl3*H2O precursor in an ethylene glycol-carbon black-NaOH mixture. However, the possibility that remnant Cl and Na from the synthesis p...
Source: Ultramicroscopy - August 19, 2023 Category: Laboratory Medicine Authors: Nicol ás A Rivas Rivas Alba Garz ón Manjón Miquel Vega-Paredes Se-Ho Kim Baptiste Gault Hosun Jun Chanwon Jung Viktoriya Berova Katharina Hengge Tilman Jurzinsky Christina Scheu Source Type: research
Chemistry and microstructure of C-supported Ru catalyst nanoparticles: A correlative study
Ultramicroscopy. 2023 Aug 11;254:113831. doi: 10.1016/j.ultramic.2023.113831. Online ahead of print.ABSTRACTRu@Pt core shell nanoparticles possess optimal catalytic properties that facilitate the anodic oxidation reaction of H2 with decreased Pt loading in hydrogen fuel cells. Moreover, since they preferentially oxidize CO, Pt poisoning is considerably reduced, which significantly improves the stability of the cell. The Ru cores used in this system are usually synthesized by dissolving a RuCl3*H2O precursor in an ethylene glycol-carbon black-NaOH mixture. However, the possibility that remnant Cl and Na from the synthesis p...
Source: Ultramicroscopy - August 19, 2023 Category: Laboratory Medicine Authors: Nicol ás A Rivas Rivas Alba Garz ón Manjón Miquel Vega-Paredes Se-Ho Kim Baptiste Gault Hosun Jun Chanwon Jung Viktoriya Berova Katharina Hengge Tilman Jurzinsky Christina Scheu Source Type: research
A method for estimating magnetic field of TEM objective lens
The objective lens magnetic field evaluation is tested on the Co/Pt multilayered films with known magnetic properties.PMID:37586244 | DOI:10.1016/j.ultramic.2023.113822 (Source: Ultramicroscopy)
Source: Ultramicroscopy - August 16, 2023 Category: Laboratory Medicine Authors: D A Tatarskiy N S Gusev S A Gusev Source Type: research
Soft X-ray Fermi surface tomography of palladium and rhodium via momentum microscopy
In this study, we explored the Fermi surface of the 4d noble metals palladium and rhodium obtained via high-resolution constant initial state momentum microscopy. The complete 3D-Fermi surfaces of palladium and rhodium were tomographically mapped using soft X-ray photon energies from 34 eV up to 660 eV. To fully capture the orbital angular momentum of states across the Fermi surface, the Fermi surface tomography was performed using p- and s- polarized light. Applicability and limitations of the nearly-free electron final state model in photoemission are discussed using a complex band structure model supported by experiment...
Source: Ultramicroscopy - August 16, 2023 Category: Laboratory Medicine Authors: Xin Liang Tan Kenta Hagiwara Ying-Jiun Chen Jakub Schusser Iulia Cojocariu Daniel Baranowski Vitaliy Feyer J án Minár Claus M Schneider Christian Tusche Source Type: research
