Optimized detector configurations for the reconstruction of phase-contrast images in scanning transmission electron microscopy.

Using the differential phase contrast mechanism and anti-symmetric detector geometries it is possible to image distributions of electric and magnetic fields in a scanning transmission electron microscope. Different detector geometries can be used for imaging and, due to their efficiency, mainly ring quadrant detectors and pixelated detectors have been used in recent high resolution differential phase contrast experiments. In 4D-Scanning Transmission Electron Microscopy one uses a pixelated (2D) detector to obtain the complete scattering distribution for every (2D) image point.

Quantitative Strain and Topography Mapping of 2D Materials Using Nanobeam Electron Diffraction.

It is known that 2D materials can exhibit a nonflat topography, which gives rise to an inherent strain. Since local curvature and strain influence mechanical, optical, and electrical properties, but are often difficult to distinguish from each other, a robust measurement technique is needed. In this study, a novel method is introduced, which is capable of obtaining quantitative strain and topography information of 2D materials with nanometer resolution.

Magnetic and Optical Properties of Gold-Coated Iron Oxide Nanoparticles.

In this work, magnetic and optical properties of magnetic nanoparticles were investigated, where the particles of iron oxide were prepared with a co-precipitation route and the component of gold was built up by reduction of AuCl on the surface of iron oxide to assemble nanocomposite structures in the form of an electrostatic stabilized suspension. The size of the particles obtained with TEM increased from of 8.9 ± 2.

Calculation of inelastic scattering processes of relativistic electrons in oriented crystals.

The inelastic scattering of electrons in oriented crystals has been used to determine the positions of atoms within a crystal, to obtain site-dependent electron energy loss spectra and, more recently, to obtain an energy loss signal corresponding to the circular dichroism in X-ray absorption spectroscopy. The theoretical approaches currently used for the description of these processes are based on the nonrelativistic Schrödinger equation. Nowadays many experiments, however, are conducted with incident energies of 200 or 300 keV.

Improving the reliability of the background extrapolation in transmission electron microscopy elemental maps by using three pre-edge windows.

Over the last decades, elemental maps have become a powerful tool for the analysis of the spatial distribution of the elements within specimen. In energy-filtered transmission electron microscopy (EFTEM) one commonly uses two pre-edge and one post-edge image for the calculation of elemental maps. However, this so called three-window method can introduce serious errors into the extrapolated background for the post-edge window.

Optimization of EFTEM image acquisition by using elastically filtered images for drift correction.

Because of its high spatial resolution, energy-filtering transmission electron microscopy (EFTEM) has become widely used for the analysis of the chemical composition of nanostructures. To obtain the best spatial resolution, the precise correction of instrumental influences and the optimization of the data acquisition procedure are very important. In this publication, we discuss a modified image acquisition procedure that optimizes the acquisition process of the EFTEM images, especially for long exposure times and measurements that are affected by large spatial drift.

Experimental evidence of self-limited growth of nanocrystals in glass.

Growth of nanocrystals precipitated in glasses with specific compositions can be effectively limited by diffusion barriers forming around crystallites. For the first time, we do experimentally prove this concept of self-limited growth on the nanoscale for a SiO(2)/Al(2)O(3)/Na(2)O/K(2)O/BaF(2) glass in which BaF(2) nanocrystals are formed. As shown by advanced analytical transmission electron microscopy techniques, the growth of these BaF(2) crystals, having great potential for photonic applications, is inherently limited by the formation of a ca.

Quantitative comparison of energy-filtering transmission electron microscopy and atom probe tomography.

Whereas transmission electron microscopy (TEM) is a well established method for the analysis of thin film structures down to the sub-nanometer scale, atom probe tomography (APT) is less known in the microscopy community. In the present work, local chemical analysis of sputtered Fe/Cr multilayer structures was performed with energy-filtering transmission electron microscopy (EFTEM) and APT. The single-layer thickness was varied from 1 to 6nm in order to quantify spatial resolution and chemical sensitivity.

Identification and localization of cyanophycin in bacteria cells via imaging of the nitrogen distribution using energy-filtering transmission electron microscopy.

In this study the technique of energy-filtering transmission electron microscopy was applied to localize cyanophycin (CGP) in recombinant strains of Ralstonia eutropha. Since CGP is a polymer consisting of the amino acids aspartate and arginine, which functions as a temporary nitrogen reserve that is deposited as insoluble inclusions in the cytoplasm of the cell, its nitrogen content is significantly higher than that of the other cell matter. In this study, we recorded nitrogen distribution maps, which represent the location of CGP in ultrathin sections of resin-embedded cells of recombinant strains of R.