TOWARDS A LOW ALPHA LATTICE FOR THE ALBA STORAGE RING

Abstract A proposal of a low alpha lattice for the ALBA third generation light source is presented. Opposed to most of other machines, belonging to the same category, ALBA employs an optimized lattice making use of combined function dipoles. This has permitted a very compact design stripped out of all not strictly necessary quadrupoles resulting in a lack of flexibility. For such a reason the common approaches used in many other synchrotrons can not be directly applied to ALBA and a different strategy has to be worked out

Electrochemical Formation of Germanene: pH 4.5

Germanene is a single layer allotrope of Ge, with a honeycomb structure similar to graphene. This report concerns the electrochemical formation of germanene in a pH 4.5 solution. The studies were performed using in situ Electrochemical Scanning Tunneling Microscopy (EC-STM), voltammetry, coulometry, surface X-ray diffraction (SXRD) and Raman spectroscopy to study germanene electrodeposition on Au(111) terraces. The deposition of Ge is kinetically slow and stops after 2–3 monolayers. EC-STM revealed a honeycomb (HC) structure with a rhombic unit cell, 0.44 ± 0.02 nm on a side, very close to that predicted for germanene in the literature. Ideally the HC structure is a continuous sheet, with six Ge atoms around each hole. However, only small domains, surrounded by defects, of this structure were observed in this study. The small coherence length and multiple rotations domains made direct observation with surface X-ray diffraction difficult. Raman spectroscopy was used to investigate the multi-layer Ge deposits. A peak near 290 cm^(−1), predicted to correspond to germanene, was observed on one particular area of the sample, while the rest resembled amorphous germanium. Electrochemical studies of germanene showed limited stability when exposed to oxygen

Economia e finanza a Roma

Il volume offre un'introduzione aggiornata all'economia, alla finanza, alla fiscalità di Roma antica

Controlling the growth mode of para-sexiphenyl(6P) on ZnO by partial fluorination

We report on the impact of partial fluorination of para-sexiphenyl (6P) on the growth mode when deposited on the non-polar ZnO(10[1 with combining macron]0) surface. The evolution of the thin film structure and morphology is monitored by in situ atomic force microscopy and in situ real-time X-ray scattering. Both 6P and its symmetrical, terminally fluorinated derivative (6P-F4) grow in a highly crystalline mode, however, with a distinctly different morphology. While 6P films are characterised by the formation of two different phases with three-dimensional nanocrystallites and consequently a rather rough surface morphology, layer-by-layer growth and phase purity in case of 6P-F4 prevails leading to smooth terraced thin films. We relate the different growth behaviour to specifics of the thin film structure.Peer Reviewe