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5 páginas, 3 figuras., Due to the growing number of applications of small diameter single wall carbon nanotubes (SWCNTs) in opto-electronics and biological imaging, there is a strong need for a better understanding of their electronic properties. Because (6,5) tubes with a diameter of 0.75 nm are currently the strongest enriched in the CoMoCat synthesis process, they are one of the most studied carbon nanotubes. However, there is still a lack of knowledge on the electronic properties of these tubes. In this paper, we report on a detailed analysis of the electronic structure of (6,4)/(6,5) enriched nanotubes with a combined experimental and theoretical approach. From photoemission the detailed C1s and valence band response of these narrow diameter tubes is studied. The observed electronic structure is in sound agreement with state of the art ab initio calculations using density functional theory., T. P. and K.DBacknowledge financial support from DFG projects PI 440 3/4/5. T. P. thanks the FWF P21333-N20 and H. S. the Leverhulme Trust for support through an early career fellowship and EPSRC through Portfolio Partnership grant. D. J. M. and A. R. thank ETSF-I3 (contract nr. 211956). We acknowledge European Community’s Seventh Framework Program (FP7/2007-2013) under grant agreement No. 226716.

Carbon based structures have been widely studied by X-ray absorption (XAS), also called NEXAFS, which is a very useful bulk probing method that allows examining the unoccupied density of states (DOS) and the site selective bonding environment. Two very well known spectral features in the XAS core level spectrum are the σ* and π* bands, and both have been analyzed in several studies for graphitic-like systems. However, among all the carbon materials, the unique one-dimensional electronic properties attributed to single-walled carbon nanotubes (SWCNTs) exhibit features that reveal clearly their electronic structure in the core level XAS spectrum. In this article, we outline the C1s response in XAS, which is related to the DOS of the conduction band in SWCNTs and its fine structure, revealed by experiments performed on metallicity-sorted SWCNT material. The progress in the identification of changes in the site selective conduction band electronic structure with XAS is discussed in detail.

A detailed study on the photoselective Raman response of p-type intercalated single-wall carbon nanotube (SWCNT) is presented. Here, we focus on the high doping region. The shift of the G-line is used to monitor the doping level of the p-type intercalated SWCNT using irontrichloride. Special emphasis is given on the changes in the dispersion of the D- and G'-lines as a function of doping. For very high doping levels a decrease of the slope is observed.

Starting from the two binary bulk glass formers in the Cu–Zr system, we systematically investigated the compositional dependence of glass formation, thermal, elastic, and mechanical properties in the Cu–Zr–Ag ternary bulk glassy alloys. Both Cu(50−x)Zr50Agx and Cu(64−x)Zr36Agx series show a good combination of high glass-forming ability and high Poisson’s ratio. However, compressive plastic deformation was only observed in Cu(50−x)Zr50Agx series and the possible underlying mechanism is discussed.

A foam synthesis method that takes advantage of the viscous high-temperature liquid state of Fe-based bulk glass-forming alloys to produce amorphous steel foam is introduced. Zirconium hydride is utilized as a foaming agent taking advantage of the low hydrogen solubility of these glass-forming alloys. Amorphous foams with porosities up to 65% were produced having homogenous cellular morphologies that exhibit cell-size uniformity. Even though intracellular solid regions as thin as a few micrometers are detected, on a global scale the cellular structure is determined to be incapable of alleviating the foam from the brittle nature of the monolithic glass.

The compositional dependence of thermal and elastic properties of Cu–Zr–Be ternary bulk metallic glass forming alloys was systematically studied. There exists a linear relationship between the glass transition temperature Tg and the total Zr concentration. G decreases linearly with increasing Zr concentration as well. The results also show that Tg, shear modulus G, and Poisson's ratio nu are very sensitive to changes in compositions. Low Tg, low G, and relatively high nu can be achieved with high Zr and Ti concentration.