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A combined single-source precursorapproach has been developedfor the deposition of thin films of Cr-doped molybdenum disulfide(MoS2) by aerosol-assisted chemical vapor deposition (AACVD).Tris(diethyldithiocarbamato)chromium(III) can also be used for thedeposition of chromium sulfide (CrS). Films have been analyzed bya range of techniques including scanning electron microscopy (SEM),energy dispersive X-ray (EDX) spectroscopy, Raman spectroscopy, andpowder X-ray diffraction (pXRD) to elucidate film morphology, composition,and crystallinity. The presence of Cr in the MoS2filmsproduces a number of striking morphological, crystallographic, andnanomechanical changes to the deposited films. The chromium dopantappears to be uniform throughout the MoS2from the scanningtransmission electron microscopy (STEM) EDX spectrum imaging of nanosheetsproduced by liquid-phase exfoliation of the thin films in N-methyl-2-pyrollidone. [ABSTRACT FROM AUTHOR]

The passage of an electric current through graphite or few-layer graphene can result in a striking structural transformation, but there is disagreement about the precise nature of this process. Some workers have interpreted the phenomenon in terms of the sublimation and edge reconstruction of essentially flat graphitic structures. An alternative explanation is that the transformation actually involves a change from a flat to a three-dimensional structure. Here we describe detailed studies of carbon produced by the passage of a current through graphite which provide strong evidence that the transformed carbon is indeed three-dimensional. The evidence comes primarily from images obtained in the scanning transmission electron microscope using the technique of high-angle annular dark-field imaging, and from a detailed analysis of electron energy loss spectra. We discuss the possible mechanism of the transformation, and consider potential applications of ‘three-dimensional bilayer graphene’. [ABSTRACT FROM AUTHOR]

Image registration and non-local Poisson principal component analysis (PCA) denoising improve the quality of characteristic x-ray (EDS) spectrum imaging of Ca-stabilized Nd2/3TiO3 acquired at atomic resolution in a scanning transmission electron microscope. Image registration based on the simultaneously acquired high angle annular dark field image significantly outperforms acquisition with a long pixel dwell time or drift correction using a reference image. Non-local Poisson PCA denoising reduces noise more strongly than conventional weighted PCA while preserving atomic structure more faithfully. The reliability of and optimal internal parameters for non-local Poisson PCA denoising of EDS spectrum images is assessed using tests on phantom data. [ABSTRACT FROM AUTHOR]