The multiparticle systems dealt with here - gases, nanosystems and fluids - involve all forms of matter that are to be categorized between particles (Constituents of Matter, Volume 4) and solids ...(Volume 6). Experiments are emphasized and in addition, all major theoretical initiatives and approximations as well as all current major discoveries are described by leading experts. Nanoparticles and functional nanosystems have been the subject of increasing interest over recent years, including for practical applications. Their production, the analysis of their physical properties and their application are fully described.
Key Features
comprehensive description of the complex field of multiparticles incorporating all current major discoveriessuitable for compiling material for self-study
When magnetic properties are analysed in a TEM using the technique of electron magnetic circular dichroism (EMCD), one of the critical parameters is the sample orientation, and this, independently on ...the chosen acquisition geometry. Since small orientation changes can have a strong impact on the EMCD measurement, it is experimentally non trivial to measure the EMCD signal as a function of sample orientation. The classical EMCD experimental setup requires to tilt the crystal in a 2 beam orientation and to acquire two electron energy loss spectra at two conjugate scattering angles. The effect of a mistilt from the perfect 2-beam orientation on the measured EMCD signals has not been explored yet due to different experimental constraints. In order to maintain the exact sample location and orientation for the acquisition of the EMCD signal, we have developed a methodology to simultaneously map the quantitative EMCD signals and the local orientation of the crystal. We analyse, both experimentally and with simulations, how the measured magnetic signals evolve with a change in the crystal tilt from the exact 2-beam orientation. Based on this analysis, we establish an accurate relationship between the crystal orientations and the EMCD signals. Our results demonstrate that a small crystal tilt away from the 2-beam orientation can significantly alter the strength and the distribution of the EMCD signals. From an optimisation of the crystal orientation, we obtain quantitative EMCD measurements.
We give an experimental demonstration of two types of recently proposed ventilator apertures which can be used to acquire electron magnetic circular dichroic (EMCD) signals in zone axis orientation ...with high spatial resolution. To simplify the experimental procedures, we propose a third type of aperture and experimentally demonstrate the use of this modified ventilator aperture for the case of multiple symmetries in the diffraction patterns. To show the feasibility of the atomic resolution EMCD, EMCD signals are acquired for a range of beam convergence angles. High quality EMCD signals with convergence angles corresponding to atomic resolution electron probes are obtained.
Die hier behandelten Vielteilchensysteme - Gase, Nanosysteme und Flüssigkeiten - umfassen alle Formen der Materie, die zwischen Teilchen (Bestandteile der Materie, Band 4) und Festkörpern (Band 6) ...einzuordnen sind. Die Experimente stehen im Vordergrund. Zusätzlich werden alle wichtigen theoretischen Ansätze und Näherungen sowie die wesentlichen aktuellen Erkenntnisse zum komplexen Gebiet der Vielteilchen von führenden Wissenschaftlern beschrieben. Insbesondere Nanoteilchen und funktionale Nanosysteme haben in den letzten Jahren für praktische Anwendungen zunehmendes Interesse gefunden. Ihre Herstellung, die Analyse ihrer zum Teil ganz neuen physikalischen Eigenschaften und ihre Nutzungsmöglichkeiten werden ausführlich dargestellt. Pluspunkte: * umfassende Darstellung des komplexen Gebiets der Vielteilchen unter Einbeziehung aller wichtigen aktuellen Erkenntnisse, * für die Erarbeitung des Stoffes im Selbststudium geeignet.
