Contribution of electron precession to the identification of the space group from microdiffraction patterns

Determination of the Crystal Structure of a New Polymorph of Theophylline

“…For example, in scanning mode (STEM) direct imaging of the crystal lattice can be coupled with spectroscopic analysis to yield chemical information at the unit cell level. [8] In imaging mode the technique is routinely used for identification and characterisation of defect structures; [9] in diffraction mode, detailed investigations of both symmetry [10] and crystal structure [11] are possible. Precision control of sample position and tilt, coupled with rapid acquisition of digital images, has contributed strongly to the development of holographic methods for the measurement of local fields within structures, [12] and tomographic approaches to three dimensional characterisation of microstructure.…”

High-pressure research using dynamic compression at the European XFEL

“…So-called ramp compression [2] using shaped nanosecond laser pulses will allow to generate states of pressure exceeding current limitations of static compression avoiding at the same time steep temperature rise following hugoniot curves. The development and implementation at European XFEL of the required optical laser system with pulse energies in the range beyond 100 J, temporal shaped nanosecond pulses and repetition rates of 0.1 to 10 Hz was recently proposed by an international consortium.…”

“…Such techniques would become extremely important in case of non-planar and microscopic sample excitation using focused optical laser pulses. [1] for detailed information about European XFEL see www.xfel.eu [2] J. Commonly, structure solution is performed using X-ray diffraction data.…”

“…Due to the fact that all studied structures had relatively high values of lattice parameters, conventional Convergent Beam Electron Diffraction method could not be used for characterization of their symmetry. For this purpose, microdiffraction technique [2] was successfully applied. Atomic model was determined by following path: observation of PED patterns from the studied phase at different orientations; extraction of the intensities and building a dataset (we have used ELD and Triple softwares [3]); use these data as an input for direct methods utilized in SIR package [4].…”

Σχέση Μικροδομής - Ιδιοτήτων Σε Υπερωστενιτικούς Ανοξείδωτους Χάλυβες

“…Μάλιςτα, ο J.P. Morniroli et al ζχει προτείνει και μία μζκοδο θ οποία βοθκά ςτθ βελτίωςθ ενόσ διαγράμματοσ θλεκτρονιακισ περίκλαςθσ, όταν οι ηϊνεσ υψθλισ διάταξθσ (HOLZ) δεν είναι καλά διακριτζσ [246,247]. Στθν ςυνζχεια, μπορεί να γίνει προςδιοριςμόσ τθσ κρυςταλλογραφικοφ προςανατολιςμοφ (Orientation Relationship -OR) που ςυνάπτει θ δευτερεφουςα φάςθ με το πλζγμα, ςτθν προκειμζνθ περίπτωςθ τον ωςτενίτθ.…”