Publications database

Bei der Messung der Inneren Reibung in polykristallinen Aluminiumdrähten fand K$\hat{e}$ /1,2/ ein Dämpfungsmaximum, das in einkristallinem Al nicht beobachtetwurde. Die Auswertung des Maximums lieferte eine Aktivierungsenergie von 1,4 eV, die im Bereich der Aktivierungsenergie der Volumenselbstdiffusion in Al liegt.Dagegen wurden von Berry und Pritchet /3/ sowie von Vollkommer et al. [...]

Gram-positive Bakterien sekretieren häufig große Proteinmengen in das Medium. Aus diesem Grund finden sie in der Industrie vielfach Anwendung in der Produktion extrazellulärer Enzyme. [...]

In view of the diverse potential applications of technetium complexes in nuclear medicine diagnostics, it is of interest to produce such complexes which behave similarly to D-hexoses in the organism. According to the current state-of-the-art, it has not yet proved possible to complex technetium in weighable quantities with hexoses or their derivatives and to determine the bio-distribution of the characteristic complexes in the organism. [...]

Strain analyses from experimental series of nano-beam electron diffraction (NBED) patterns in scanning transmission electron microscopy are performed for different specimen tilts. Simulations of NBED series are presented for which strain analysis gives results that are in accordance with experiment. [...]

Surface enhanced Raman spectroscopy (SERS) has been established as a powerful tool to detect very low-concentration bio-molecules. One of the challenging problems is to have reliable and robust SERS substrate. [...]

A high-speed direct electron detection system is introduced to the field of transmission electron microscopy and applied to strain measurements in semiconductor nanostructures. In particular, a focused electron probe with a diameter of 0.5 nm was scanned over a fourfold quantum layer stack with alternating compressive and tensile strain and diffracted discs have been recorded on a scintillator-free direct electron detector with a frame time of 1 ms. [...]

A detailed understanding of structure and stability of nanowires is critical for applications. Atomic resolution imaging of ultrathin single crystalline Au nanowires using aberration-corrected microscopy reveals an intriguing relaxation whereby the atoms in the close-packed atomic planes normal to the growth direction are displaced in the axial direction leading to wrinkling of the (111) atomic plane normal to the wire axis. [...]

The built-in piezoelectric fields in group III-nitrides can act as road blocks on the way to maximizing the efficiency of opto-electronic devices. In order to overcome this limitation, a proper characterization of these fields is necessary. [...]

Solid-state properties such as strain or chemical composition often leave characteristic fingerprints in the angular dependence of electron scattering. Scanning transmission electron microscopy (STEM) is dedicated to probe scattered intensity with atomic resolution, but it drastically lacks angular resolution. [...]